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In the backdrop of today's environmental priorities, where toxicity and stability hinder lead‐based perovskite solar cell (PSC) progress, the emergence of lead‐free alternatives like Cs2AgBiBr6 perovskites has gained significance. This study revolves around the comprehensive evaluation of Cs2AgBiBr6 as a potential photovoltaic (PV) material, using density functional theory (DFT) calculations with CASTEP. Revealing a vital bandgap of 1.654 eV and emphasizing the contributions of Ag‐4d and Br‐4p orbitals, this analysis also underscores Ag atoms' dominance in charge distribution. Optically, Cs2AgBiBr6 exhibits UV absorption peaks around 15 eV, intensifying with photon energy up to 3.75 eV, hinting at its promise for solar applications. Guided by DFT, forty configurations involving various electron transport layers (ETLs) and hole transport layers (HTLs) are explored. Among these, CNTS emerges as the prime HTL due to ideal absorber alignment. The spotlight architecture, FTO/AZnO/Cs2AgBiBr6/CNTS/Au, boasts exceptional efficiency (23.5%), Voc (1.38 V), Jsc (21.38 mA cm−2), and FF (79.9%). In contrast, FTO/CdZnS/Cs2AgBiBr6/CNTS/Au achieves a slightly lower 23.15% efficiency. Real‐world intricacies are probed, encompassing resistances, temperature, current–voltage (J–V) traits, and quantum efficiency (QE), enhancing practical relevance. These findings are thoughtfully contextualized within prior literature, showcasing the study's contributions to non‐toxic, inorganic perovskite solar technology. This work aspires to positively steer sustainable PV advancement. [ABSTRACT FROM AUTHOR]

This work mainly focuses on synthesizing and evaluating the efficiency of methylammonium lead halide‐based perovskite (MAPbX3; X=Cl, Br, I) solar cells. We used the colloidal Hot‐injection method (HIM) to synthesize MAPbX3 (X=Cl, Br, I) perovskites using the specific precursors and organic solvents under ambient conditions. We studied the structural, morphological and optical properties of MAPbX3 perovskites using XRD, FESEM, TEM, UV‐Vis, PL and TRPL (time‐resolved photoluminescence) characterization techniques. The particle size and morphology of these perovskites vary with respect to the halide variation. The MAPbI3 perovskite possesses a low band gap and low carrier lifetime but delivers the highest PCE among other halide perovskite samples, making it a promising candidate for solar cell technology. To further enrich the investigations, the conversion efficiency of the MAPbX3 perovskites has been evaluated through extensive device simulations. Here, the optical constants, band gap energy and carrier lifetime of MAPbX3 were used for simulating three different perovskite solar cells, namely I, Cl or Br halide‐based perovskite solar cells. MAPbI3, MAPbBr3 and MAPbCl3 absorber layer‐based devices showed ~13.7 %, 6.9 % and 5.0 % conversion efficiency. The correlation between the experimental and SCAPS simulation data for HIM‐synthesized MAPBX3‐based perovskites has been reported for the first time. [ABSTRACT FROM AUTHOR]

The stability and performance challenges in conventional 3D perovskite solar cells (PSCs), attributed to perovskite structure and transport layers, prompt the exploration of 2D perovskites. However, the presence of transport layers and conventional contacts is still challenging as it creates interface defects and pinholes. In this study, a new transport‐layer‐free device structure, i.e., MXene–2D perovskites–MXene‐based metal–semiconductor–metal PSCs, is introduced to resolve the stability‐ and performance‐related issues. The proposed solar cell incorporates PeDAMAPb2I7 as the absorber layer and MXenes (Hf2NF2/Ta4C3F2) as electrodes. The Dion–Jacobson perovskites solar cell is also investigated for optimum thickness and defect tolerance level of PeDAMAPb2I7. In the results, it is indicated that the device delivered the maximum efficiency of 5.63% at a 500 nm thick absorber layer with a defect density of 1 × 1013 cm−3. Further, the quest to find suitable MXene contact for electron extraction is met by analyzing the proposed solar cell with nine different MXene layers (Hf2NF2, Hf2CF2, Zr2NF2, Ta2CF2, Ti4C3, Ti3C2, Zr2C, Sc2C, Ti2C). In the results, it is indicated that Hf2NF2 has a 3.2 eV work function, making it the optimal choice, achieving 5.63% efficiency. [ABSTRACT FROM AUTHOR]

The new form of renewable energy attracts enormous attention from researchers for its immense importance and impact on our daily life. A fossil energy is a non‐renewable source that will end shortly because of its immense use in houses and industries. Among the renewable sources, solar cells based on perovskite (PVK) materials exponentially increase their efficiency from 3.8% to 25.8% rapidly in a diminutive period of time. In the present study, doped and undoped PVK layers (MAPbI3, MAPb[I1‐xClx]3) are considered and optimized for solar cell application by using the SCAPS‐1D device simulator. A detailed investigation is done in terms of PVK absorber layer (PAL) thickness variation with different electron and hole transport layers, temperature, and bulk defect density to optimize the device performance. The MAPb(I1‐xClx)3‐based device delivered the highest conversion efficiency of ~29% with JSC of 25.59 mA/cm2, VOC of 1.348 Volt, and an FF of about 83.68%. Results reported in this work may pave the way for the development of advanced high‐efficiency PVK solar cells. [ABSTRACT FROM AUTHOR]

The trapping of photons and broad-spectrum absorption of solar irradiance are the primary focus of numerous solar cell research applications. In the current work, a novel paradigm for trapping light is introduced by introducing a nano-pyramidal array (NPA) using the SETFOS simulator. The triple layer used in the optimized design of the PSC helps improve photon absorption inside the device. The current study shows the optimization of carrier transport layer (CTL) thickness, temperature, cathode materials, and defectivity of the PSC devices. The simulation confirms that the NPA on the top of the ITO combined with a triple-graded active layer (AL) exhibits a current density (JSC) of 21.43 mA cm−2, an open-circuit voltage (VOC) of 0.835V, a fill factor (FF) of 82.37, and a power conversion efficiency (PCE) of 14.73%, respectively. The study also includes a lower-cost and novel TaTm as the hole transport layer (HTL) and C60 as the electron transport layer (ETL) for suitable band alignment with the photon absorber. Hence, combining the triple grading with NPA and TaTm as HTL efficiently improves the device performance and shows an effective way to optimize the PSC devices. [ABSTRACT FROM AUTHOR]

In the rapid growth of perovskite solar cells, there are still specific issues regarding the extensive absorption of incident photons. Double-layered methyl ammonium (MA)-free perovskite solar cells (PSC) have been proposed to sort out these issues. The material absorber in solar cells based on MA-free and cesium-based perovskite, i.e., Cs2BiAgI6, is a critical parameter because of its non-volatile nature as well as its band gap of 1.6 eV being helpful in a broader visible absorption spectrum than the conventional CH3NH3PbI3 material. Moreover, the quantum efficiency (QE) and power conversion efficiency (PCE) in a configuration with MXene + TiO2 as the electron transport layer (ETL) in the PSC can make improvements over a more extensive range. The results of the current modeling of numerical simulations are used to investigate the exclusive optoelectrical outputs of the PSC. Furthermore, we use a novel approach of an ETL of MXene + TiO2 in a PSC, which will lower the manufacturing cost and defectiveness. The present work compares different ETLs to attain the best PCE using Cs2BiAgI6 as a perovskite absorber layer (PAL). The results are exciting as the highest open circuit voltage (VOC) of 1.48 V, high short current density (JSC) of 22.8 mA cm-2, with a high fill factor (FF) of nearly 84.6% in the double-layered PSC offer a high power conversion efficiency (PCE) of more than 28%. The designed outputs will be efficient for the convenient fabrication of the PSC. [ABSTRACT FROM AUTHOR]

According to recent reports, planar structure-based organometallic perovskite solar cells (OPSCs) have achieved remarkable power conversion efficiency (PCE), making them very competitive with the more traditional silicon photovoltaics. A complete understanding of OPSCs and their individual parts is still necessary for further enhancement in PCE. In this work, indium sulfide (In2S3)-based planar heterojunction OPSCs were proposed and simulated with the SCAPS (a Solar Cell Capacitance Simulator)-1D programme. Initially, OPSC performance was calibrated with the experimentally fabricated architecture (FTO/In2S3/MAPbI3/Spiro-OMeTAD/Au) to evaluate the optimum parameters of each layer. The numerical calculations showed a significant dependence of PCE on the thickness and defect density of the MAPbI3 absorber material. The results showed that as the perovskite layer thickness increased, the PCE improved gradually but subsequently reached a maximum at thicknesses greater than 500 nm. Moreover, parameters involving the series resistance as well as the shunt resistance were recognized to affect the performance of the OPSC. Most importantly, a champion PCE of over 20% was yielded under the optimistic simulation conditions. Overall, the OPSC performed better between 20 and 30 °C, and its efficiency rapidly decreases above that temperature. [ABSTRACT FROM AUTHOR]

To meet the increasing demand for power sources, scientists are continuously trying to improve the efficiency of solar cells. In these circumstances, Cs-based perovskites have attracted attention due to their intriguing performance. In this paper, eight different solar cells based on Cs-halide perovskite absorbers (CsPbI3, CsPbBr3, CsSnI3, CsSnCl3, Cs2BiAgI6, Cs3Bi2I9, CsSn0.5Ge0.5I3, and Cs3Sb2I9) are investigated using the SCAPS-1D simulation program. Besides, ZnO and CFTS materials are proposed as promising candidates for charge transport material application, along with gold as the back contact. Initially, the impact of the absorber and the electron transport layer (ETL) thickness on the photovoltaic performance was evaluated. In addition, various parameters, such as the thickness, the donor and acceptor densities and the defect density, are investigated to locate the final optimized Cs-based structures. From this optimization, it is evident that among all the optimizing features, absorber materials and the hole transport layer (HTL) thickness, the HTL acceptor density enhanced the performance much more than the other optimizing features. Furthermore, to evaluate the characteristics of these devices, the series resistance, shunt resistance, working temperature, current–voltage density, and quantum efficiency are also simulated. Among all eight Cs-based perovskites, the ITO/ZnO/CsPbBr3/CFTS/Au and ITO/ZnO/Cs3Bi2I9/CFTS/Au devices achieved the best performance, with a conversion efficiency of 19.28% and 19.23%, respectively. Lastly, the performance of the SCAPS-1D simulator software is verified using the wxAMPS simulation program, where both yield results that are in excellent agreement. In conclusion, this research provides useful information for optimizing solar cell architectures and understanding the effects of various device components. [ABSTRACT FROM AUTHOR]

In this study, we investigated the potential of CsPbI3 as an absorber material to be used in perovskite solar cells (PSCs). To optimize the device, we used TiO2 as the electron transport layer and copper barium thiostannate (CBTS) as the hole transport layer in the CsPbI3-based PSC, and employed SCAPS- 1D software. We initially tested 10 different back metal contacts (BMCs) to identify the most suitable one for the primary device. After optimization of the BMC, the best-optimized device structure, ITO/TiO2/CsPbI3/CBTS/Ni, achieved a power conversion efficiency of 17.91%. We then evaluated the impact of the absorber thickness, acceptor density, and defect density on the device performance. We also analyzed the effect of changing the thickness, charge-carrier density, and defect density of the CsPbI3, TiO2, and CBTS layers, as well as the interfacial defect densities at the CBTS/CsPbI3 and CsPbI3/TiO2 interfaces, to further optimize device performance. This resulted in an improved efficiency of 19.06% for the ITO/TiO2/CsPbI3/CBTS/Ni device with HTL, compared to 18.17% without HTL. We also analyzed the impacts of operating temperature, series resistance, and shunt resistance on the final optimized device performance, as well as its capacitance-voltage, generation and recombination rate, current density- voltage (J-V), and quantum efficiency (QE) features. The results of these simulations provide valuable insights for the experimental fabrication of an efficient CsPbI3-based inorganic PSC. [ABSTRACT FROM AUTHOR]

Lead-free perovskite (LFP) materials are leading the photovoltaic (PV) market due to their nontoxic nature and good optoelectronic properties. It also increases the reliability and stability of perovskite solar cells (PSC). However, the performance of such materials is not upto the mark due to some inherent losses. Therefore, in this paper, the concept of a two-terminal monolithic tandem solar cell is utilized to mitigate the non-absorbed photon loss of the lead-free wide bandgap (1.8 eV) halide (WBH) PSC. For efficient absorption of top cell filtered spectrum, bottom cell has been designed with CZTSSe (1.1 eV) as active layer and tin (II) sulfide (Sn2S3) as back surface layer. Both LFP based top cell and CZTSSe based bottom cell have been analyzed under standalone conditions. Thereafter, to analyse the tandem configuration top cell is illuminated with AM1.5 G spectrum while for the bottom cell the unabsorbed spectrum by top cell has been used. To account for the mandate requirement of tandem cell designing current matching approach is utilized and LFP-CZTSSe tandem solar cell has been designed to deliver an efficiency of 16.6%. The obtained result shows the best current matching condition at 380 nm thick LFP and 550 nm thick CZTSSe, respectively, with a short circuit current density (JSC) of 14.9 mA/cm2. The final tandem device showed the power conversion efficiency of 16.6% with an open-circuit voltage (VOC) of 1.7 V. The obtained conversion efficiency is higher compared to till date experimental standalone conversion efficiency of LFP solar cells. Therefore, the proposed LFP-CZTSSe tandem solar cell would be a strong candidate in the PV industry delivering high efficiency at a cheap cost. [ABSTRACT FROM AUTHOR]

• A comprehensive study of lead-free PSCs are accomplished using SCAPS-1D simulating software. • The novel approach of grading of the active layer is also studied. • The CTM combination of Titanium oxide (TiO 2) and 2,2′,7,7′-Tetrakis[ N , N - di (4- methoxyphenyl) amino ]-9,9′-spirobifluorene. (SpiroOMeTAD) attains the best possible device outputs. • The lesser defective MASnI3 layer at optimal thickness offers excellent efficiency of 22.3%. • The present work can be valuable for futuristic device optimization of PSC. Methylammonium tin iodide (MASnI 3) is the most commonly used lead-free perovskite absorber material to resolve the issues related to toxic lead (Pb)-based MAPbI 3 perovskite. However, conversion efficiency for MASnI 3 -based perovskite solar cells (PSCs) are still struggling to compete with lead-based PSCs. Therefore, this study provides a roadmap to achieving 22.3 % conversion efficiency for MASnI 3 -based PSCs through extensive device modeling. The work utilizes the graded active layer approach to attain higher excitons inside the active layer. The opto-electrical model's combined effort is considered an excellent light trapping mechanism by matching precise bandgaps 1.3 eV/1.3 eV for a higher generation of excitons. Detailed investigation and optimization of single, double, and triple graded perovskite absorber layer (PAL) have been done in terms of absorber layer thickness, temperature, back contact materials, and bulk defect density to achieve a conversion efficiency of 22.3 %. Results revealed that double-graded perovskite outperforms compared to single and triple-graded material and delivered excellent photovoltaic (PV) parameters such as short circuit current density (J SC) of 33.51 mAcm−2, open-circuit voltage (V OC) of 875 mV and fill factor (FF) of 75.93 %. This paper provides a smooth pathway for futuristic development and further optimization of the device lead-free MASnI 3 -based PSCs. [ABSTRACT FROM AUTHOR]

Multi‐junction solar cells connecting two or more cells with significantly different bandgaps have a lot of promise for exceeding the Shockley Queisser (S‐Q) efficiency limit of single‐junction‐based photovoltaic devices. In this article, a new class of tandem devices has been proposed and investigated for improved efficiencies. The proposed tandem cell is connected in monolithic two‐terminal tandem configurations with wide bandgap formamidinium (FA) based perovskite absorber (FA0.85 Cs0.15 Pb (I0.85 Br0.15)3) (1.6 eV) (Cs15/Br15)) on the top cell and low bandgap gallium free chalcogenide (CuInSe2) absorber on the bottom cell. Doped FA‐based perovskite material is preferred over commonly used FAPbI3 as it is a proven fact that adding modest quantities of cesium and bromine stabilizes the optically active black phase of FAPbI3 Perovskite and increases overall device performance. In contrast, bottom CuInSe2 (CIS) absorber material is selected considering its good thermal stability and excellent light‐absorbing capabilities in a broad‐spectrum range. The feasibility of the suggested tandem configuration is assessed in two steps. First, a 1.6 eV perovskite top cell is simulated and calibrated to suit the state‐of‐the‐art power conversion efficiency of 17.5 %, followed by a 1.04 eV CuInSe2‐based bottom cell with a calibrated efficiency of 16.2 %. Both devices are tested for tandem configuration once the standalone (top and bottom) subcells have been calibrated. At varied absorber thicknesses in both the top and bottom subcells, the current matching conditions are achieved. At optimal thicknesses of 700 nm and 590 nm for the bottom and top absorbers, respectively, the overall tandem structure obtained an excellent power conversion efficiency of 25.13 %. Results reported in this study may pave the way for the development of high‐efficiency perovskite/CIS based tandem solar cells in the future. [ABSTRACT FROM AUTHOR]

This present work emphasizes the numerical modeling of lead-free methylammonium tin tri-iodide (MASnI3)-based perovskite solar cells (PSCs) under optimizing preconditions. The prior selection of the perovskite material of MASnI3 is feasible for a more extended absorption spectrum due to a smaller bandgap of 1.3 eV than higher bandgap methylammonium lead tri-iodide (MAPbI3)-based PSC and the factor of lesser toxicity. Furthermore, to enhance the efficiency of the device, selecting potentially steadier and superior carrier transport materials (CTMs) is among the most effective approaches for optimizing device outputs. Among the proposed materials, a prior selection of copper antimony sulfide (CuSbS2) and zinc oxide (ZnO) as CTMs with an optimized thickness of MASnI3 material has offered a higher power conversion efficiency (PCE) of 22.16% under the photoillumination AM1.5. Furthermore, the less-defective PSC device can also be helpful for further device optimization and futuristic development. [ABSTRACT FROM AUTHOR]

In conventional perovskite solar cells (PSCs), a thin active layer of perovskite is sandwiched between two charge transport layers (CTLs)–electron transport layer (ETL) and hole transport layer (HTL). CTLs help in extracting and navigating the photogenerated electron–hole (e-h) pairs to the respective electrodes. Although this phenomenon gives high-energy conversion efficiencies but leads to quite a few performances as well as fabrication challenges. The ways to partially overcome these challenges are to have a device without the need of having CTLs altogether and opting for the back-contact (BC) design for PSCs. Dipole fields (DFs) present at the metal perovskite interface may be thought for their possible utilization to have CTL-free BC PSC. However, the performance of such devices is limited by the difference between the metal work functions across the perovskite layer. In this article, we report the results for our studies to establish that an electrostatically doped DF-assisted metal perovskite metal back-contact (ED-DF-MPM) PSC structure has the ability to overcome the limitations of DF-assisted metal perovskite metal back-contact (DF-MPM) PSCs. As a part of the work carried out here, ED p-n-junction and corresponding built-in potential have been combined for DF-assisted extraction of generated carriers within the perovskite layer so as to enhance the collection probability and open-circuit voltage. Quantitively, 32.7%, 10.6%, and 8.6% improvement in short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF) are obtained, respectively, which resulted in an observation of 59.4% improvement in power conversion efficiency (PCE) for ED-DF-MPM PSC compared to DF-MPM PSC. Besides that, the reported ED-DF-MPM PSC structure delivers the photovoltage and photocurrent of 659 mV and 14.19 mA ⋅ cm−2, respectively. The work reported in this article may pave the way for the development of “transport layer-free” ED scalable and low-cost PSCs in future. [ABSTRACT FROM AUTHOR]

A multijunction or tandem technique comprising a wide bandgap top cell and a narrow bandgap bottom cell may be a major stepping stone in an attempt to obtain high-efficiency solar cells. However, easier said than done, it takes a lot to correctly optimize the structure of all the involved layers so as to possibly obtain the desired results. In this paper, a perovskite (CH3NH3PbI3)/FeSi2 (p-i-n structure) 2-terminal (2-T) monolithic tandem solar cell is proposed and investigated using AFORS-HET v2.5 1D simulator. A hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon oxide (µc-Si1−xOx:H) tunnel recombination junction is employed to interconnect both perovskite and FeSi2 solar cell for current matching. The influence of both top and bottom absorber layer thickness is analyzed to optimize the device performance. The study reveals an optimized 26.3% efficient perovskite/FeSi2 monolithic tandem solar cell with JSC (21.4 mA cm−2), VOC (1.63 V), and FF (74.86%). The results in this paper suggest FeSi2 material with 0.87 eV bandgap as an alternative for narrow bandgap bottom cell for the perovskite-based tandem solar cells so as to obtain much higher efficiencies. [ABSTRACT FROM AUTHOR]

Abstract This work presents an extensive study of one of the potential alternatives in electron transport material (ETM) for perovskite solar cell (PSC). Reduced cerium oxide (CeO x) as an electron transport layer (ETL) is studied for different composition of oxygen and analysis with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) interface layer thickness if stacked in between CeO x ETL and perovskite layer has also been done. A detailed investigation has been carried out, incorporating the mobility of CeO x due to small polaron hopping mechanism at the different composition of x, the effect of variation in doping concentration for CeO x and PCBM have also been studied and the optimum efficiency 18.2% is obtained for PSC. Furthermore, to improve the shortcomings in terms of hysteresis and moisture stability, a device is proposed incorporating carbon nanotube (CNT) layer stacked between perovskite and hole transport layer (HTL) which shows 18.6% conversion efficiency. Graphical abstract Image 1 Highlights • Simulation analysis has been done for CeO x based electron transport layer (ETL). • Incorporated the mobility in CeOx due to small polaron hopping mechanism at different composition of x. • 18.2% efficient perovskite device has been simulated using CeO 1.96 (ETL) and PCBM as interfacial layer. • Moreover, CNT stacking has also been projected to minimize the moisture degradation. • Finally, 18.6% efficient CNT and CeO x based device is proposed, which will be free from hysteresis and moisture. [ABSTRACT FROM AUTHOR]

• AI - driven optimization of low lead Zn-based CsPb 0.625 Zn 0.375 I 2 Cl, all inorganic perovskite solar cells (AIHP-SC) with the help of SCAPS-ID simulator generated data set. • Transport layer optimization is performed by varying mobility and doping density, ETL/HTL doping is varied for the range for 0.004 cm2/Vs to 4 cm2/Vs, while the range of ETL/HTL doping density is 1015 cm−3 to 1019 cm−3. • A significant rise in PCE is observed from 9.5% to 21.90% while optimizing ETL/HTL mobility and doping density of AIHP-SC. • SCAPS-ID generated data set of 2500 steps are utilized for machine learning implementation. • SHAP analysis uncovers transport layer parameters shaping perovskite solar cell behavior. • Time-efficient approach integrating AI for stable and efficient solar cell design. Perovskite-based solar cells have captivated researchers, due to their outstanding photovoltaic (PV) performance. All inorganic halide perovskite solar cells (AIHP-SC) exhibited excellent stability against environmental conditions with improved lifetime. In this investigation, low lead CsPb 0.625 Zn 0.375 I 2 Cl based AIHP-SC is designed with the utilization of a SCAPS-1D simulator. Further, the impact of ETL/HTL parameters viz. mobility and doping on the PV performance is analyzed. Thereafter, machine learning (ML) models are trained, tested, and verified using artificial intelligence (AI) algorithms. Utilization of ML models shortens experiment time and eliminates the requirement for extensive resources in designing and predicting the PV performance of solar cells. In this research, the PV performance of AIHP-SC layered as TiO 2 / CsPb 0.625 Zn 0.375 I 2 Cl/ Spiro-MeOTAD at different ETL/HTL mobility (ranging from 0.004 cm2/Vs to 4 cm2/Vs) and doping density (ranging from 1015 cm−3 to 1019 cm−3) has been evaluated. The influence of these variations leads to the generating 2500 PV performance datasets including current density (J SC), fill factor (FF), open circuit voltage (V OC), and power conversion efficiency (PCE). These generated data set attributes are fed to train the ML models viz. linear regression (LR), random forest (RF), support vector regression (SVR), eXtreme gradient boosting (xGB), and artificial neural network (ANN). For validation, the performance of ML models is verified against SCAPS-1D generated performance results by using mean square error (MSE) and R square (R2) as the performance metrics. Execution of ML algorithms revealed that performance of RF and xGB exhibits high correlation with SCAPS-1D generated data set as the prediction made by these two algorithms are best matched to actual outcome. Additionally, Shapley additive explanations (SHAP) analysis is performed to examine the influence of input variables (also known as independent variables) on target performance parameters (V OC , J SC , FF and PCE). A significant rise in PCE is observed from 9.5 % to 21.90 % while optimizing ETL/HTL mobility and doping density of AIHP-SC. The investigated results provide supervision to researchers in the design of highly stable AIHP-SC, further integration of ML in AIHP-SC is time time-efficient approach to design and performance prediction. [ABSTRACT FROM AUTHOR]

In this study, a novel 10 μm thick interdigitated back contact silicon-germanium heterojunction (IBC-Si 1- x Ge x HJ) solar cell device has been designed and simulated for standalone and four-terminal mechanically stacked tandem applications. Optimization of i-a-SiGe: H thickness, the width of n-a-SiGe: H region, p-a-SiGe: H region and gap along with composition fraction ( x ) lead to 15.5% power conversion efficiency (PCE) in a stand-alone configuration. Whereas in combination with perovskite top subcell we further demonstrate 25.7% PCE in four-terminal tandem configuration. In mechanical stacking, top and bottom subcells are fabricated individually and then assembled in a module, which avoids the need for current matching between subcells, thereby giving greater process and design flexibility. The proposed IBC-SiGeHJ solar cell is ∼ (25–30) times thinner than conventional Si solar cells which are used as bottom subcell in perovskite/silicon tandem solar cell. The results reveal that the proposed 4-terminal mechanically stacked perovskite/IBC-SiGeHJ tandem device may open new doors for the energy efficient applications. All the simulations have been done using Silvaco technology computer aided design (TCAD) simulator. [ABSTRACT FROM AUTHOR]

In this work, a novel four-terminal perovskite/SiC-based rear contact silicon tandem solar cell device has been proposed and simulated to achieve 27.6% power conversion efficiency (PCE) under single AM1.5 illumination. 20.9% efficient semitransparent perovskite top subcell has been used for perovskite/silicon tandem architecture. The tandem structure of perovskite-silicon solar cells is a promising method to achieve efficient solar energy conversion at low cost. In the four-terminal tandem configuration, the cells are connected independently and hence avoids the need for current matching between top and bottom subcell, thus giving greater design flexibility. The simulation analysis shows, PCE of 27.6% and 22.4% with 300 μm and 10 μm thick rear contact Si bottom subcell, respectively. This is a substantial improvement comparing to transparent perovskite solar cell and c-Si solar cell operated individually. The impact of perovskite layer thickness, monomolecular, bimolecular, and trimolecular recombination have also been obtained on the performance of perovskite top subcell. Reported PCEs of 27.6% and 22.4% are 1.25 times and 1.42 times higher as compared to experimentally available efficiencies of 22.1% and 15.7% in 300 μm and 10 μm thick stand-alone silicon solar cell devices, respectively. The presence of SiC significantly suppressed the interface recombination in bottom silicon subcell. Detailed realistic technology computer aided design (TCAD) analysis has been performed to predict the behaviour of the device. [ABSTRACT FROM AUTHOR]

2D-perovskite has attracted notable interest for its ability to address the stability challenges related to traditional 3D-perovskite. Using proper contacts for 2D-perovskites is crucial to effectively eliminate pinhole creation and collect carriers. Therefore, in this study, MXene contacts have been employed with 2D-DJ-perovskite (DJP) solar cells to combine both benefits, resulting in enhanced stability, superior charge transport, and tunable energy levels without pinhole effects. Further, to improve efficiency and mitigate transmission-thermalization losses, this work also harnesses the remarkable tunable bandgap property of the DJ-P. The DJ-P layer's bandgap is adjusted by modifying its composition in this work. This is achieved by varying the number of inorganic layers (n) within the (PeDA)(MA) n-1 Pb n I 3n+1 , perovskite structure, ranging from 1 to 6 across the thickness of the DJ-P layer. Linear, parabolic, beta, and power law-grading profiles are employed in the DJP solar cell to determine the optimal composition for the DJ-P layer. The results demonstrate that power law grading yields the highest efficiency, reaching a maximum of 17.47 % with 1.05 V V OC. [ABSTRACT FROM AUTHOR]

Low-cost materials are used in this work to make a triple-junction tandem solar cell (TSC). Two-step filtered spectrum and current matching techniques are used to design a perovskite-CIGS-SnS based TSC using a SCAPS-1D simulator. To design a TSC, the top cell (TC) is illuminated with a 1.5AM spectrum, and the unabsorbed spectrum of the TC is utilized for the middle cell (MC). Similarly, the unabsorbed spectrum of the MC is used to illuminate the bottom cell (BC). Additional merits of this work: the perovskite used is a two-dimensional Dion Jacobson (DJ) perovskite, which is more stable than conventional perovskites. The results show that current matching is obtained at active layer thickness (nm) of 365/600/100 for TC/MC/BC, respectively. The proposed solar cell shows a remarkable PV performance of 3.25 V V OC , 9.42 mA/cm2 J SC , 79.3 % FF and 24.27 % PCE. • Low-cost triple-junction tandem solar cells are utilized in this work to reduce thermalization and transmission losses. • Two-step filtered spectrum and current matching techniques are used to design a perovskite-CIGS-SnS-based TSC using a SCAPS-1D simulator. • Additional merits of this work is the perovskite used is a two-dimensional Dion Jacobson (DJ) perovskite, which is more stable than conventional perovskites. • This study conducted a thorough analysis and identified the ideal thicknesses (nm) of 365/600/100 for the top/middle/bottom absorber layers, respectively. • The proposed solar cell shows a remarkable PV performance of 3.25 V V OC , 9.42 mA/cm2 J SC , 79.3 % FF and 24.27 % PCE. [ABSTRACT FROM AUTHOR]

• Bandgap engineering scheme has been implemented to improve the PV performance of lead-free all inorganic perovskite CsSnI 3-x Br x based solar cell. • The results shows that linear grading achieves a maximum PCE of 21.68%. • Parabolic grading while varying bowing factor from 0 to 1 has attained a PCE of 23.61%. • Further, different ETLs and HTLs are investigated to check the compatibility. • The SnO 2 / PEDOT identified as best ETL and HTL and delivered PCE of 24.30%. In the modern era of technology, worldwide paradigms have been shifted toward the utilization of green energy. Sun energy is the most astonishing eco-friendly resource of energy and can be harnessed with the help of photovoltaic cells. Hybrid (Organic-Inorganic) perovskite solar cells (PSCs) are emerged with incredible photovoltaic (PV) performance. Nevertheless, a significant challenge lies in their lower stability under diverse environmental conditions. To deal with this challenge, all inorganic cesium-based PSC has been studied and analyzed, results improved stability in comparison to hybrid PSC. However, the noxious nature of lead is deleterious to the environment. So, this work primarily aimed, to study lead-free all inorganic tin-based perovskite compound CsSnI 3-x Br x , as the main light absorber layer. Further, to elevate the PV performance of PSC, bandgap grading is performed on CsSnI 3-x Br x by varying bromide concentration x from 0 to 3. Bandgap grading encourages the absorption of a wide range of the light spectrum, by modulating bandgap (E g) / affinity(χ) through the distance of the CsSnI 3-x Br x layer. Additionally, it enhances light-generated charge carrier separation and collection by end electrodes. In this work, two different strategies have been adopted, linear and parabolic. During linear grading, the impact of variation in x (0 to 3) has been analyzed over the thickness 50–––500 nm in 10 linear steps for CsSnI 3-x Br x. The highest PCE fetched from linearly graded layered FTO / CeO 2 / CsSnI 3-x Br x / CFTS / Gold PSC is 21.68 %. Similarly, in the parabolic graded absorber layer, the influence of change in the bowing factor (0 to 1), has been analyzed relative to different values of x (0 to 3). With improvement in PV performance, the maximum PCE delivered by parabolic-graded PSC is 23.61 %. Additionally, this work extends to check the compatibility of distinct electron transport layers (ETLs) and hole transport layers (HTLs). Upon analysis, it has been found that the best PV performance was obtained while selecting SnO 2 / PEDOT as ETL / HTL respectively. [ABSTRACT FROM AUTHOR]

• All-perovskite tandem solar cell is designed and simulated. • 10.1% efficient, lead (Pb) free perovskite, Cs 2 AgBi 0.75 Sb 0.25 Br 6 (1.8 eV) based cell is used for top cell. • 14.2% efficient, low content Pb based perovskite, FACsPb 0.5 Sn 0.5 I 3 (1.2 eV) based cell is used for bottom cell. • Enhanced open circuit voltage (V OC = 1.83 V) is simulated in all-perovskite tandem design. • Optimized tandem design showed a conversion efficiency of 17.3%. Present research paper brings forth the results of simulation-based studies carried out on all-perovskite tandem (both top and bottom subcells made up of perovskites) multijunction devices. The all-perovskite tandem structure presented in this work employs a wide bandgap perovskite, i.e., Cs 2 AgBi 0.75 Sb 0.25 Br 6 (1.8 eV) and a narrow bandgap perovskite, i.e., FACsPb 0.5 Sn 0.5 I 3 (1.2 eV) as top and bottom cell respectively. An additional merit of the reported work is projection of lead (Pb)-free perovskite, Cs 2 AgBi 0.75 Sb 0.25 Br 6 and low Pb content-based perovskite, FACsPb 0.5 Sn 0.5 I 3 based tandem solar cell. The viability of proposed tandem design is performed in two steps firstly, 1.8 eV perovskite-based top cell is simulated and calibrated to fit the state-of-the-art conversion efficiency of 10.1%, and then, 1.2 eV perovskite-based bottom cell is simulated to have a calibrated efficiency of 14.2%. After calibrating the standalone (top and bottom) subcells, both the devices are evaluated for tandem configuration. The current matching conditions between the top and bottom cell is obtained at different thicknesses of the absorber layer in both top and bottom subcell. The optimized thickness for perovskite, 380 nm for top cell and 400 nm for bottom cell are obtained for tandem configuration. Top and bottom cells (fed with the filtered spectrum) reflect the conversion efficiency of 10.01% and 7.36%, respectively. Overall, tandem design showed a conversion efficiency of 17.3% owing to an enhancement in open-circuit voltage (V OC), which is 1.83 V. [ABSTRACT FROM AUTHOR]

• Cs₂CuBiCl₆ based perovskite solar cell explored. • Optimization of thickness, density and doping performed. • Machine learning models (XGBoost, RF) implemented for PCE prediction. • XGB outperforms RF (R-squared: 99.97 %, low MSE: 0.0014). Conventional perovskite materials offer reasonable power conversion efficiency (PCE) but are plagued by stability issues. To address this, researchers have explored alternative materials, such as MA and FA-based lead or lead-free perovskites, known for their improved PCE and stability. In this study, we focused on a cesium (Cs)-based cell, Cs₂CuBiCl₆, which not only exhibits acceptable PCE but also demonstrates superior stability compared to traditional perovskite materials. To optimize the Cs₂CuBiCl₆-based cell, we conducted simulations varying parameters like thickness, bulk defect density (BDD), and doping. The optimized PCE for the Cs₂CuBiCl₆-based cell reached 10.30 %. We generated 1000 datasets through simulations, which serve as input for machine learning (ML) algorithms, including random forest (RF) and XGboost (XGB). The XGB model outperformed the RF model, achieving a higher R-squared value (R2: 99.97 %) and a lower mean squared error (MSE: 0.0014). [ABSTRACT FROM AUTHOR]

Conventional perovskite-based solar cells (PSCs) have emerged as promising candidates for next-generation solar energy due to their remarkable features, including a high absorption coefficient, tunable bandgaps, high mobility, low maintenance cost, and high power conversion efficiency (PCE). However, the major bottleneck in commercialization of conventional PSCs is their poor stability (of few days), and toxicity concerns (due to lead content). To address these challenges cesium-based perovskites are widely adopted by researchers. However, detailed understanding of these devices considering several device parameters and their connection with overall PCE is not comprehensively disclosed in previous findings. Therefore, in this study, the PV performance of six (6) different PSCs with Cs-based absorber layer (CAL) viz. CsPbI 3 , CsPbBr 3 , CsSnCl 3 , CsSnI 3 , Cs 2 AgBiBr 6 and CsSn 0.5 Ge 0.5 I 3 has been investigated through SCAPS simulator, followed by developing few machine learning models to forecast the efficiency. Total 2160 dataset has been obtained by varying the absorber layer, thickness, and doping and defect density for training and testing the five different machine learning algorithms such as linear regression (LR), support vector regression (SVR), neural network (NN), random forest (RF), and XGBoost (XGB). The XGB algorithm outperforms other approaches, achieving an impressive R2 of 99.99 % and low MSE of 0.0006. Impact of each input variable on the efficiency is also obtained by generating SHAP plot for each model which revealed that absorber layer and it thickness variation greatly affected the PCE and least impact of doping is observed on PCE. Among all the absorbers, CsPbI 3 shows promising performance by delivering a maximum PCE of 14.00 %. Results reported in this work along with developed ML models may pave the way in the development of Cs based PSCs without the need of complex device simulations. • Investigated six different PSCs with Cs-based materials CsPbI 3 , CsPbBr 3 , CsSnCl 3 , CsSnI 3 , Cs 2 AgBiBr 6 and CsSn 0.5 Ge 0.5 I 3. • Five different supervised machine learning models are employed on 2160 datasets using Python. • SHAP plots are generated to visualize the impact of each feature on the conversion efficiency. • XGB outperformed other algorithms, achieving an impressive R2 value of 99.99 % and a low MSE of 0.0006. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimized Cs 0.05 FA 0.95 PbI 2.55 Br 0.45 layer for solar windows and BIPV. • Achieved 20 % PCE, 1.24 V V OC , and 80.70 % fill factor. • Increased J SC from 9.98 to 21.60 mA/cm2 with thinner absorber layers. • Balanced transparency and efficiency for building-integrated photovoltaics. Perovskite materials are gaining attention due to their superior photovoltaic performance and potential for transparent solar cell applications, such as solar windows and building-integrated systems. This study focuses on designing thinner Cs 0.05 FA 0.95 PbI 2.55 Br 0.45 perovskite layers to balance transparency and power conversion efficiency (PCE). The solar cell performance improves with increased absorber layer thickness, resulting in a current density (J SC) rise from 9.98 to 21.60 mA/cm2. The optimized device achieves an open-circuit voltage (V OC) of 1.24 V, a fill factor (FF) of 80.70 %, and PCE of 20 %. For absorber thicknesses of 100–500 nm, the PCE ranges from 10.01 % to 19.45 %, while the average visible transmittance (AVT) decreases from 51.05 % to 2.63 %. These results provide insights into designing semi-transparent perovskite solar cells with a balance between efficiency and transparency. [ABSTRACT FROM AUTHOR]

1. Efficiency of power conversion for both kinds of inorganic as well as organic perovskites-based cells has increased in the last few years. 2. FTO (window layer)/TiO 2 (ETL)/(PDA)(MA) n-1 Pb n I 3n+1 (absorber layer)/Cs x (FA 0.4 MA 0.6) 1-x PbI 2.8 Br 0.2 (absorber layer)/ spiro-OMeTAD (HTL). 3. DJ and RP phases of 2D PSC are individually found much more stable than their 3D counterpart used for perovskite-based solar cells. 4. DJ and RP are merged to become proof of the efficiency as well as environmental stability of 2D perovskite-based solar cells. 5. This work has been carried out by using Solar Cell Capacitance Simulator (SCAPS) – 1D. Fig. (a) Structure of device showing Dion- Jacobson (DJ) 2D-3D Perovskite Based devices within AM1.5-Spectrum, (b) Spectrum showing absorption of various substances used in the device structure. [Display omitted] • Efficiency of power conversion for both inorganic and organic perovskites-based cells has increased in last few years. • FTO (window layer)/TiO 2 (ETL)/(PDA)(MA) n-1 Pb n I 3n+1 (absorber layer)/Cs x (FA 0.4 MA 0.6) 1-x PbI 2.8 Br 0.2 (absorber layer)/ spiro-OMeTAD (HTL). • DJ and RP phases of 2D PSC are individually found more stable than their 3D counterpart used for perovskite-based solar cells. • DJ and RP are merged to become proof of efficiency as well as environmental stability of 2D perovskite-based solar cells. • This work has been carried out by using Solar Cell Capacitance Simulator (SCAPS) – 1D. Efficiency of power conversion for both kinds of inorganic as well as organic perovskites-based cells has increased in the last few years. To overcome this stability-related issue of 3D perovskite cells,2D perovskite has become an alternative option.The structure and the device, both are destabilized by the weak interactions observed in between the layers of the layered perovskite since the Ruddlesden Popper (RP) phase of 2D perovskite has a weak Van der Waal gap present in between the monoammonium cation layer.The PCE of perovskite cells has risen to 25 %. Commercialization of perovskites on a large scale as solar is a challenging task because lead is toxic.Keeping the toxic property of lead in mind we have used FTO (window layer)/TiO 2 (ETL)/(PDA)(MA) n-1 Pb n I 3n+1 (absorber layer)/Cs x (FA 0.4 MA 0.6) 1-x PbI 2.8 Br 0.2 (absorber layer)/ spiro-OMeTAD (HTL).It has been observed that the DJ and RP phases of 2D PSC are individually found much more stable than their 3D counterpart used for perovskite-based solar cells. DJ and RP are merged to become proof of the efficiency as well as environmental stability of 2D perovskite-based solar cells.Several material parameters that affect the performance result obtained from the device,like the electron transport layer(ETL), hole transport layer(HTL), the thickness of the absorbing layer,etc were considered,studied,and also have been optimized. [ABSTRACT FROM AUTHOR]

• The study models BaZrS 3 solar cells, alloying Ti at the Zr site for bandgap engineering at concentrations up to 3%. • Various back surface fields (BSFs) (CdTe, CIGS, CZTSe, Cu 2 Te, FeSi 2 , GeSe, PbS, µc-Si, SnTe, SnS, Sn 2 S 3 , and WSe 2) are investigated to enhance photo-absorption. • Comparative study of BaZrS 3 -based solar cells with BSFs with already existing structures of BaZrS 3 solar cells without BSFs. • The findings indicate that a Ti alloying concentration of 3% at the Zr site, coupled with a Cu 2 Te BSF, achieves the highest efficiency, approximately 30%. Chalcogenide perovskites are emerging as superior alternatives to hybrid halide perovskites for photovoltaic applications due to their non-carcinogenic composition and enhanced environmental resilience, including superior resistance to moisture. This study focuses on the computational modeling of BaZrS 3 (Barium Zirconium Sulfide) based solar cells, featuring a native bandgap of ∼1.71 eV. Through precise bandgap engineering via Ti alloying at the Zr site, the study aims to optimize the bandgap to the ideal range for photovoltaic efficiency. The device architecture is further refined by adjusting parameters such as layer thickness, doping densities, trap densities and metal contacts. The optimum device efficiencies at this stage were found to be 22.45 % for BaZrS 3 ; 23.91 % for Ba(Zr 0.99 Ti 0.01)S 3 ; 26.64 % for Ba(Zr 0.98 Ti 0.02)S 3 ; and 27.74 % for Ba(Zr 0.97 Ti 0.03)S 3. Additionally, the incorporation of various back surface fields (BSFs) (CdTe, CIGS, CZTSe, Cu 2 Te, FeSi 2 , GeSe, PbS, µc-Si, SnTe, SnS, Sn 2 S 3 , and WSe 2) is investigated to enhance photo-absorption. The findings indicate that a Ti alloying concentration of 3 % at the Zr site, coupled with a Cu 2 Te BSF, achieves the highest efficiency, approximately 30 %. These optimized structures present a robust framework for developing efficient, stable, and non-toxic photovoltaic devices utilizing chalcogenide perovskites. [ABSTRACT FROM AUTHOR]

Over the previous few decades, numerous scientific and theoretical approaches have been employed to increase solar cell efficiency. To improve PV cell efficiency, this study employs grading methodologies and modifies temperature, series resistance, different defect densities, and graded layer thickness. The paper presents a theoretical examination of the linearly graded device structure (Au/PTAA/CsPbBr 3-x I x /TiO 2 /FTO). A linearly graded perovskite layer, responsible for absorbing a wide range of light spectra with different wavelengths, assists in bettering the solar cell's characteristics. In this device, polytriarylamine (PTAA) acts as an HTL, and TiO 2 acts as an ETL. SCAPS-1D, a simulation program, is used for our theoretical analysis. The output results obtained from the simulation are as follows: PCE of 20.50 %, J SC of 18.071 mA cm−2, V OC of 1.4531 V, and FF of 78.08 %. • A theoretical examination of the linearly graded device structure (Au/PTAA/CsPbBr3-xIx/TiO2/FTO). • A linearly graded perovskite layer with different wavelengths, assists to better the solar cell's characteristics. • Poly triarylamine (PTAA) acts as an HTL, and TiO2 acts as an ETL. • SCAPS-1D, a simulation program, is used for our theoretical analysis. • The output results obtained are: PCE of 20.50 %, J SC of 18.071 mA-cm−2, V OC of 1.4531 V, and FF of 78.08 %. [ABSTRACT FROM AUTHOR]

Perovskite (PVK) materials with wide-bandgap (W BG) play a crucial role in achieving high-performance tandem devices but phase segregation and open-circuit voltage (V OC) loss hinders in surpassing the efficiency of single-junction solar cells. Present work discloses a numerical simulation which has been carried out using a W BG material CH 3 NH 3 PbI 3-x Cl x of bandgap (E g) 1.65eV as an absorber layer of the top cell (T CELL) and a Cu(In,Ga)Se 2 -based cell having narrow-bandgap (N BG) of E g (1.27eV) has been used as bottom cell (B CELL). The T CELL utilizes polyethyleneimine ethoxylated (PEIE) interfacial layer to promote charge-collection and charge-tunneling. The T CELL and B CELL have been optimized by various optimization processes such as simultaneous thickness variation of active-region with defect density (DD), variation of interface defect density (IDD) with solar-cell parameters a commendable power conversion efficiency (PCE) of 27.06 %, and 26.77 % has been achieved for respective solar-devices. Variations of numerous electron transport layer (ETL) and hole transport layer (HTL) have also been performed to acquire highly optimized T CELL. Thus, a perovskite/CIGS tandem solar cell (PVK/CIGS-TSC) device has been obtained using filtered-spectra analysis and current-matching (method which display a promising photovoltaic (PV) parameter with a high V OC of 2.29 V, short-circuit current density (J SC) of 17.41 mA/cm2, fill factor (FF) of 86.45 % and PCE of 34.47 %. These discoveries hold significant promise for the future development of TSCs. [Display omitted] • CH 3 NH 3 PbI 3-x Cl x of bandgap (E g) 1.65eV as an absorber layer of the top cell (T CELL) and a Cu(In,Ga)Se 2 -based cell having narrow-bandgap (N BG) of E g (1.27eV) has been used as bottom cell (B CELL). • The T CELL and B CELL have been optimized with its defect density (DD), variation of interface defect density (IDD) with solar-cell parameters a commendable power conversion efficiency (PCE) of 27.06 %, and 26.77 %. • Variations of various electron transport material (ETM) and hole transport material (HTM) have also been performed to further optimize the T CELL. • A tandem perovskite solar cell (TP SC) device has been accomplished with a high V OC of 2.29 V, short-circuit current density (J SC) of 17.41 mA/cm2, fill factor (FF) of 86.45 % and PCE of 34.47 %. • These discoveries hold significant promise for the future development of TP SC. [ABSTRACT FROM AUTHOR]

In this study, the perovskite tandem solar cell (TP SC) has been accomplished using SCAPS-1D. The present study focuses on comprehensive exploration and detailed optimization using various strategies constructing a tandem device. To calculate high photovoltaic power conversion efficiency (PCE), the numerical analysis has been carried out for a wide-bandgap halide (W BH) FA 0.75 Cs 0 · 25 Pb(I 0 · 8 Br 0.2) 3 of bandgap 1.67eV and a Pb–Sn based narrow-bandgap halide (N BH) FA 0.7 MA 0.3 Pb 0 · 5 Sn 0 · 5 I 3 of bandgap 1.22eV as absorber layer in top-cell (T CELL) and bottom-cell (B CELL) respectively. The W BH has huge potential as a front light absorber and the N BH based B CELL provides stability and high performance by accepting high and low energy photons respectively. This method mitigates thermalization and non-absorbed photon loss which results in the growth in PCE. The proposed work demonstrates the impact of active-layer thickness along with defect density on the solar-cell parameters. It has been observed that defect density is low for the optimal performance. An investigation for various electron transport medium (ETMs) and hole transport medium (HTMs) has been done to secure an optimum performing T CELL as well as B CELL. Using filtered-spectrum study along with current-matching method, every PV metric parameter has been analyzed after their deployment into tandem configuration. The numerical investigation has shown promising photovoltaic parameters with aa high open circuit voltage (V OC) of 2.33 V, a short circuit current density (J SC) of 17.07 mA/cm2, a fill factor (FF) of 79.34 % and PCE of 31.55 % in tandem configuration. • Perovskite tandem solar cell (TP SC) has been accomplished using SCAPS-1D. • Wide-bandgap halide (W BH) FA 0.75 Cs 0 · 25 Pb(I 0 · 8 Br 0.2) 3 of bandgap 1.67eV and a Pb–Sn based narrow-bandgap halide (N BH) FA 0.7 MA 0.3 Pb 0 · 5 Sn 0 · 5 I 3 of bandgap 1.22eV as absorber layer in T CELL and B CELL respectively have been studied. • Open circuit voltage (V OC) of 2.33 V, a short circuit current density (J SC) of 17.07 mA/cm2, a fill factor (FF) of 79.34 % and PCE of 31.55 % in tandem configuration. • Using filtered-spectrum study along with current-matching method, every PV metric parameter has been analyzed after their deployment into tandem configuration. • The proposed work demonstrates the impact of active-layer thickness along with defect density on the solar-cell parameters. [ABSTRACT FROM AUTHOR]

This paper includes the theoretical investigation performed on the device having structure FTO/TiO 2 /CH 3 NH 3 PbI 3 /PeDAMAPb 4 I 16 /Spiro- OMeTAD. This work is focused on the effects of ETLs and HTLs on the performance of the device structure. Device simulation and various parameters of the perovskite cell are investigated with the help of SCAPS-1D software. In recent years, perovskite solar cells (PSCs) have passed through many advancements but they suffered through instability due to moisture. Due to poor stability of PSCs becomes a major obstacle for its commercialization. This leads to the development of 2D perovskite manufactured from organic cations and inorganic slabs arranged alternately.2D perovskite is of two kinds: Ruddlesden - Popper (RP) phase and Dion-Jacobson (DJ) phase. Both types of 2D perovskite are observed to be much more stable than 3Dperovskite. Due to its stability, it becomes an alternative for 3D perovskite. To improve the stability and efficiency of 2D perovskite both types of 2D phases are merged. To have more stability organic cations are introduced between inorganic slabs which reduces charge transportation. Proposed DJ 2D-3D perovskite solar cells provide an impressive efficiency of 26.03 % even when exposed to much temperature and moisture. Being much more efficient and stable the 2D-DJ/3D perovskite becomes an option to be utilized in photovoltaic applications. • This paper includes theoretical investigation having device structure FTO/TiO 2 /CH 3 NH 3 PbI 3 /PeDAMAPb 4 I 16 /Spiro- OMeTAD. • To improve the stability and efficiency of 2D perovskite both types of 2D phases are merged. • To have more stability organic cations are introduced between inorganic slabs which reduces charge transportation. • Proposed DJ 2D-3D perovskite solar cells provide an impressive efficiency of 26.03 % in more temperature and moisture also. • Being much more efficient and stable the 2D-DJ/3D perovskite becomes an option to be utilized in photovoltaic applications. [ABSTRACT FROM AUTHOR]

• Investigates a solar cell with SnO2 (ETL), fullerene (C60), KGeCl3, and Me4PACz layers. • SCAPS 1d generated 1000 datasets: VOC: 1.13V, JSC: 23.47 mA/cm², FF: 73.34%, PCE: 19.62%. • Uses ML algorithms, especially XGBoost (XGB), to predict PCE with high accuracy. • XGB shows highest R² (99.60%) and lowest MSE (0.150) in predictions. The existing designs of perovskite based solar cells frequently encounter issues with poor photovoltaic (PV) performance and stability issues. In this study, to address above issues, we investigate a novel solar cell device featuring layers of tin dioxide (SnO 2), fullerene (C 60), potassium germanide chloride (KGeCl 3), and Me4PACz. SnO 2 , serving as the electron transport layer (ETL), offers high electron mobility and compatibility with solution processing techniques. Further, different machine learning (ML) algorithms have been utilized for the prediction of accurate PCE prediction in order to simplify computations and improve accuracy. The complex interactions between these parameters and their combined impact on device stability and efficiency are shown through systematic experimentation with SCAPS 1d and 1000 datasets have been generated. Impressive PV parameters are obtained by optimization: V OC : 1.13 V, J SC : 23.47 mA/cm2, FF: 73.34 %, and PCE: 19.62 %. Ensemble machine learning techniques, such as XGBoost (XGB), perform better than individual models, exhibiting increased accuracy and resilience across a range of machine learning performance metrics. When compared to individual SVR, RF and stacked SVR & RF the MSE value produced by the XGB (0.150) algorithm is significantly lower. However, out of all the ML algorithms in this study, the R2 value found in XGB (99.60 %) is the best. The boosting strategy used by XGB is notable for how well it handles complicated datasets and enhances PCE prediction in solar cells. After finding the best suited models (RF & XGB), mean and standard deviation have also been calculated for the different ML performance matrices like MSE, R2 and CVS for 10 iterations. The development of innovative perovskite base PSCs without the need for tedious and lengthy simulations may be facilitated by this approach. [ABSTRACT FROM AUTHOR]

[Display omitted] • Initial Structure: FTO/CdS/Cs 2 AgBi 0.75 Sb 0.25 Br 6 /HTL/Au structure was examined to determine how ten-hole transport layers (HTLs) affect solar cell efficiency. • Optimized Structure: The FTO/ETL/Cs 2 AgBi 0.75 Sb 0.25 Br 6 /MoO 3 /Au structure has been investigated with six electron transport layers (ETLs) (BaSnO 3 , PC 61 BM, SnS 2 , Ti 2 O 3 :Nb, CdS, ZnOS) to find the best combination. • Material Tuning: Cs 2 AgBi 0.75 Sb 0.25 Br 6 absorber, ETLs like BaSnO 3 , PC 61 BM, SnS 2 , Ti 2 O 3 :Nb, CdS, ZnOS thickness, donor and defect density. • Quantum Efficiency: Achieved nearly 100% EQE within the visible spectrum, showcasing optimized light absorption. The present study delves into the utilization of computer modeling techniques to analyze a photovoltaic (PV) design incorporating a lead (Pb)-free perovskite absorber material. This innovative structure employs a cesium-based double perovskite material, specifically Cs 2 AgBi 0.75 Sb 0.25 Br 6 , characterized by an energy bandgap of 1.80 eV. The Cs 2 AgBi 0.75 Sb 0.25 Br 6 exhibits a range of advantageous properties, including heightened stability in ambient conditions and appropriately aligned bandgaps. Given these considerations, an extensive exploration of the FTO/CdS/Cs 2 AgBi 0.75 Sb 0.25 Br 6 /HTL/Au configuration was undertaken to assess the impact of ten distinct hole transport layers (HTLs) on the solar cell's efficiency. The simulation and analysis of all devices were conducted employing the one-dimensional SCAPS-1D (Solar Cell Capacitance Simulator) tool. Furthermore, the efficiency of the FTO/ETL/Cs 2 AgBi 0.75 Sb 0.25 Br 6 /MoO 3 /Au architecture was probed, employing six different electron transport layers (ETLs) (BaSnO 3 , PC 61 BM, SnS 2 , Ti 2 O 3 :Nb, CdS, ZnOS), to discern the optimal combination. Post-optimization, adjustments were made to the absorber and ETL thickness, as well as the acceptor doping and defect density of the absorber, and the donor and defect density of the ETL, for the six combinations assessed. These topologies were also examined for their impacts on series and shunt resistance, capacitance, the Mott-Schottky effect, generation and recombination processes, current–voltage density, and quantum efficiency. Eventually, the most efficient cell in this study achieved a power conversion efficiency (PCE) of 30.30 % and featured the FTO/ZnOS/Cs 2 AgBi 0.75 Sb 0.25 Br 6 /MoO 3 /Au configuration. The aforementioned findings hold significant potential for advancing lead-free, double perovskite solar cells (PSCs) that are both more efficient and environmentally sustainable, paving the way for their widespread adoption in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stability concerns of 3D perovskites are addressed by using 2D layer perovskites. • MXene contacts are used to mitigate the pinhole effects in perovskite solar cells. • The thickness of the BDA active layer varies with different MXene compositions. • In order to reduce thermalization and transmission losses, grading of a BDA DJ-perovskite layer is performed. • The results show that 24.6 % efficiency can be achieved with 1 µm thick BDA. In the midst of the growing emphasis on renewable energy sources, there is an urgent requirement for materials that are devoid of lead and non-toxic, aligning with the demands of the 21st century. In this regard, the perovskite solar cells present themselves as a compelling option, offering cost-effectiveness and non-toxic nature. Nevertheless, these 3D perovskite materials encounter stability challenges. To mitigate these issues, 2D DJ (Dion Jacobson) perovskite material-based solar cells are increasingly utilized in contemporary applications. In this work, (BDA)(MA) n−1 Pb n I 3n+1 -based 2D DJ perovskite solar cells (BDPSC) are investigated. Further, it is crucial to use proper contact with BDPSC in order to eliminate the pinhole effect. Therefore, in this study, MXene contacts have been employed with BDPSC to combine the benefits of both, resulting in enhanced stability, superior charge transport, and tunable energy levels without pinhole effects. Further, the bandgap of the BDA active layer is adjusted by varying the number of inorganic layers (n) from 1 to 6 within the (BDA)(MA) n−1 Pb n I 3n+1. Firstly, the thickness of the BDA active layer along with different MXene are varied for all the possible compositions of the (BDA)(MA) n−1 Pb n I 3n+1. The result shows that the optimized thickness for the BDA layer is 1 µm, and the work function value of the left/right contact MXene is 3.56/5.65 eV. Additionally, this work also investigates the influence of grading on the PV performance of BDPSC. The result shows that the reported BDPSC can deliver a maximum open circuit voltage (V OC) is 1.18 V, short circuit current density (J SC) is 24.58 mA/cm2, Fill Factor (FF) is 84.96 % and efficiency is 24.58 %. [ABSTRACT FROM AUTHOR]

• Explored 3T-APTSC to overcome single-junction solar cell limitations, especially the SQ limit. • Demonstrated the superiority of three-terminal tandems, optimizing current matching and allowing independent adjustments. • Optimized PV parameters for 3T-APTSC: V OC 3.76 V, J SC 10.70 mA/cm2, FF 69.00 %, PCE 26.24 %. Despite numerous publications on two-junction tandems using SCAPS-1D simulation, there is a gap in research regarding three-junction tandems. This paper explores the advantages of three junction all-perovskite tandem solar cells (3J-APTSC) where we introduce a new methodology utilizing two-step filtered spectrum and current matching techniques in SCAPS-1D to design realistic tandem solar cells. Crucial steps involve determining filtered spectrum and current matching points among sub-cells for tandem optimization. Our designed three-terminal tandem solar cell exhibits promising photovoltaic parameters, including V OC : 3.76 V, J SC : 10.70 mA/cm2, FF: 69.00 %, and PCE: 26.24 %, achieved through optimized active layer thicknesses. This thorough examination of 3J-APTSC offers insights that could drive the future development of highly efficient tandem solar cells. [ABSTRACT FROM AUTHOR]

Perovskite solar cells have become the main source of attraction among photovoltaic researchers since its inception in 2009 due to their steady enhancement in efficiency and cost-effective fabrication methodologies. The integration of the concept of multijunction or tandem technology with Perovskite solar cells is considered to be one of the best substitutes for designing efficient Solar Cells. Recently, the perovskite/silicon tandem architecture possesses tremendous research potential owing to their capability to generate competitive efficiencies. In this research article, we have analysed the optoelectronic properties of CsGeI 3 with the WIEN2K tool for first principle computations through the density functional theory methodology. The bandgap of CsGeI 3 is found out to be 1.6 eV. Calculated bandgap and absorption coefficient spectra are used as input parameters for device simulation using the SCAPS-1D tool. Environment-friendly CsGeI 3 and c-Si are used as top cell and bottom cell absorbers respectively with the two cells connected in series with an ITO interconnecting layer for the proposed tandem solar cell architecture. Under current matching scenario and AM 1.5G spectrum illumination, the standalone top cell shows PCE of 18.31 %, V oc ∼1.20 V, J sc ∼17.55 mA/cm2 and FF ∼86.42 % for 265 nm thick CsGeI 3 layer, while bottom cell when subjected to the spectrum transmitted by top cell, provided a PCE of 10.15 % with V oc ∼ 0.703 V, J sc ∼17.50 mA/cm2 and FF ∼82.62 % with 400 μm thick c-Si absorber. Before being implemented in the tandem configuration, simulated J-V characteristics of both top and bottom cells are calibrated to show close agreement with the experimental results. The two-terminal tandem device demonstrates an improved PCE of 28.43 %, FF of 84.90 %, J sc of 17.55 mA/cm2, and V oc of 1.90 V. The effect of R s and R sh and the interfacial and bulk defect states on the photovoltaic parameters (PCE, FF J sc , and V oc) is also analysed. Finally, a semi-analytical model is used to validate the J-V characteristics of the tandem architecture obtained with SCAPS-1D simulator using an equivalent circuit model of two series-connected diodes. This study can open new directions for the design of eco-friendly lead-free perovskite/c-Si based tandem devices with superior photovoltaic characteristics. • Investigation of the photovoltaic performance of CsGeI 3 -on- c -Si tandem solar cell using SCAPS-1D. • Electronic and optical properties of CsGeI 3 computed using WIEN2K within the framework of DFT. • The effect of series and shunt resistance, thickness, and defect density of CsGeI 3 on PV performance studied. • The tandem solar cell exhibited a PCE of 28.43 %, FF of 84.9 %, J sc of 17.55 mA/cm2, and V oc of 1.90 V. [ABSTRACT FROM AUTHOR]

• Investigations on structural, electronic, and optical properties of novel Ba 3 SbI 3 perovskite using the DFT. • The PV performance of novel Ba 3 SbI 3 based structures with non-toxic ZnS ETLs was investigated and optimized using SCAPS-1D. • The quantum efficiency, current density–voltage, generation, and recombination rates were investigated in details. • The maximum PCE of 30.49 % was achieved with J SC of 54.63 mA/cm2, FF of 83.75 %, and V OC of 0.67 V in optimized condition. The inorganic Ba 3 SbI 3 perovskite has emerged as a promising, stable absorber material for efficient and cost-effective solar cells, owing to its intriguing compositional, structural, electrical, and optical properties. This study delves into the potential of Iodide-based Ba 3 SbI 3 perovskites, known for their relative stability, as absorbers in conjunction with a ZnS electron transport layer (ETL) to create a high-performance solar cell heterostructure. Using the SCAPS-1D simulator, we first estimate the absorption spectrum and bandgap of the Ba 3 SbI 3 absorber layer through density functional theory (DFT). This obtained spectrum serves as a crucial input for device simulation. We further optimize the work function of the rear electrode to enhance the photovoltaic (PV) performance of the ZnS/Ba 3 SbI 3 heterostructure solar cell. Various parameters including doping density, absorber thickness, and bulk/interface defect density are carefully considered. Additionally, we investigated generation and recombination rates, current density-voltage (J-V) characteristics, and corresponding quantum efficiency (QE). Under optimized conditions, our study achieves a remarkable maximum power conversion efficiency (PCE) of 30.49 %, accompanied by a photocurrent density (J SC) of 54.63 mA/cm2, fill factor (FF) of 83.75 %, and open circuit voltage (V OC) of 0.67 V in the ITO/ZnS/Ba 3 SbI 3 /Ni structure. This comprehensive analysis offers valuable insights and methodologies for the experimental design of high-performance and stable photovoltaic devices based on Ba 3 SbI 3 perovskite. [ABSTRACT FROM AUTHOR]

In the exponential growth of perovskite solar cells (PSCs), there remains certain concerns regarding the wide-range incident photons absorption. The doubly graded lead-free absorber in the PSC has been recommended for solving these problems. The absorber material in the PSC is based on the lead-free as well as tin-based perovskite i.e., CH 3 NH 3 SnI 3 , that is one of the precarious parameters due to the non-toxic behavior as well as the lower band gap of 1.3 eV that can be useful in broad visible absorption spectrum than the traditional CH 3 NH 3 PbI 3 layer. Furthermore, the quantum efficiency (QE) as well as the power conversion efficiency (PCE) in the double-graded configuration of the PSC can be improve. The outcomes of the present numerical simulations examine the solar cells' single and double grading strategy. Further, we use a novel approach of HTL-free PSC, that can lower the manufacturing cost and the defectivity. The present work compares single and double-grading Perovskite Absorber Layer (PAL) for obtaining high PCE. The results are exciting as the highest open-circuit voltage (V OC) of 0.965V, higher short-current density (J SC) of 35.26 mA/cm2, and high fill factor (FF) of 86.40% in the doubly-graded PSC shows a much-optimized PCE of nearly 29.35% that can be convenient for fabricating much efficient PSC device. • The double graded absorber were simulated for higher performance parameters. • The HTL free along with optimized graded approach enhanced the efficiency. • An optimum power conversion efficiency of 29.35% was achieved using the novel technique. • The current study will pave the way for the development of highly efficient solar cells in the future. • The present work can be valuable for futuristic device optimization of tin-based solar cells. [ABSTRACT FROM AUTHOR]

Although perovskite solar cells (PSCs) have shown considerable advancement in recent years, their extensive usage is hindered by the major challenge of ensuring long-term stability. However, the enhanced stability of 2D-structure Dion-Jacobson (DJ) phase halide perovskites makes them a promising alternative to the traditional 3D perovskites, suggesting potential for broader application. In this numerical simulation, bulky organic ammonium spacer pentamethylenediamine (PeDA) was incorporated into DJ perovskite films with four different layer numbers (n = 3, 4, 5, and 6), which correspond to PeDAMA 2 Pb 3 I 10 , PeDAMA 3 Pb 4 I 13 , PeDAMA 4 Pb 5 I 16 , and PeDAMA 5 Pb 6 I 19 , respectively. Various parameters were adjusted to assess their impact on device performance. A current density–voltage (J-V) characterization was conducted for each value of n to compare their efficiencies. The number of layers was found to significantly influence efficiency, with the highest performance achieved at n = 6, resulting in an open-circuit voltage (V OC) of 1.27 V, a short-circuit current density (J SC) of 22.83 mA/cm2, a power conversion efficiency (PCE) of 21.17%, and a fill factor (FF) of 72.72%. These results demonstrate the potential of DJ perovskite solar cells with PeDA spacers as stable and efficient alternatives for photovoltaic applications. • Bulky organic ammonium spacer was incorporated into 2D-DJ perovskites with four different layer numbers. • DJ perovskite solar cells were simulated and optimized using SCAPS tool. • The number of layers significantly influenced the efficiency, with the highest performance achieved at n = 6. [ABSTRACT FROM AUTHOR]

Lead-free perovskite of cesium tin chloride (CsSnCl 3) is being considered as a potential environmentally acceptable alternative for highly efficient perovskite solar cells (PSCs) for the outstanding optoelectronic properties and reduced biotoxicity and non-hazardous characteristics. The poisonous nature and poor environmental stability of lead (Pb)-based perovskite are major hurdles to their reliable applications, even though their power conversion efficiency (PCE) has exceeded 25%. In this research, the potential of thermally stable, non-toxic CsSnCl 3 perovskite for designing high-efficiency solar cells was explored using the SCAPS-1D software. The influence of CsSnCl 3 layer thickness, acceptor density, and defect density was studied to obtain optimum values as a reference cell, and the effect of these parameters on six electron transport layers (ETLs) as well as Cu 2 BaSnS 4 (CBTS) hole transport layer (HTL) was also evaluated. The impact of series resistance, shunt resistance, and the working temperature on the electrical parameters of the cell and corresponding quantum efficiency were also assessed. The ITO/ZnO/CsSnCl 3 /CBTS/Au heterostructure was found to be the most efficient device among six different configurations, with a champion PCE of 23.96%, J SC of 23.5 mA/cm2, V OC of 1.04 V, and FF of 86%. These results were validated by results obtained from the wxAMPS and a comparative study with recent reports was also performed. These validated simulation results provide a greater understanding of the eco-friendly CsSnCl 3 -based perovskite and its potential for applications in modern prominent photovoltaic and optoelectronic devices. [Display omitted] • Here, CsSnCl 3 -perovskite SC was investigated using SCAPS-1D for efficiency improvement. • Impact of absorber, ETL, and HTLs' thickness, acceptor and defect densities were evaluated. • Effect of series and shunt resistances, temperature, and quantum efficiency was also assessed. • ITO/ZnO/CsSnCl 3 /CBTS/Au heterostructure was found to be most efficient (PCE = 23.96%). • SCAPS-1D results were compared with literature and also validated by wxAMPS simulation. [ABSTRACT FROM AUTHOR]

The wide photon absorption range of tandem solar cells (TSCs) allows them to deliver higher efficiencies than single-junction solar cells. The top cell with a wide bandgap absorbs the higher energy photons, while the bottom cell with a relatively low bandgap absorbs the filtered lower energy photons. However, for cheap, efficient, and long-lasting solar cells, the design must incorporate the top and bottom cell absorber layers with an appropriate band gap. In this context, this article proposes all-perovskite tandem solar cells with suitable perovskite partners as active materials in both the upper (band gap 1.68 eV) and the lower (band gap 1.16 eV) sub-cell. This research has retrieved the calibrated top cell from a previous publication, and the bottom cell has been designed, calibrated, and optimised. The filtered spectrum of the upper cell is evaluated at different perovskite thicknesses and fed to the lower cell to set up a tandem configuration. Subsequently, the current- matching technique has been used to study the tandem short-circuit current density (J SC) at different thicknesses of both sub-cells, followed by current density-voltage (J-V) curve. A total of ten tandem J-V curves are constructed and corresponding PV parameters are obtained to obtain the optimized efficiency of 33.8% with an open circuit voltage (V OC) of 2.15 V, a fill factor (FF) of 78.87% and a J SC of 20 mA.cm−2. The reported results will open the door for future development of highly efficient and low-cost monolithic two-terminal tandem devices. [ABSTRACT FROM AUTHOR]

• Magnesium fluoride (MgF 2) textured perovskite solar cell is proposed. • The impact of ten different MgF 2 textured surfaces is examined. • Textured device showed significant improvement as compared to device (22.7%). • The study revealed that the proposed PSC device achieved 24.8% efficiency. • Device delivered enhanced short circuit current density of 26.12 mA/cm2. In this work, we explored the use of magnesium fluoride (MgF 2) based textured surfaces in perovskite solar cells (PSCs) to enhance light trapping and increase conversion efficiency. We studied the impact of different positions of random pyramid arrays (RAs) on reflectance, EQE, JV curve, and PV parameters. Our results showed that this approach led to a conversion efficiency of 24.8% with J SC of 26.12 mA/cm2. [ABSTRACT FROM AUTHOR]

There are several types of organometallic halide perovskite solar cells (OHPSCs), but the carbon-based PSC has the lowest materials/fabrication cost and the longest-term stability, making it the most promising for practical application. In this study, we used multi—walled carbon nanotubes (MWCNTs) as the hole transport layer in the PSC architecture. We experimentally achieved an optimized efficiency of 13.7% for a MWCNTs-based device. Besides, this research describes a simulation-guided optimization process to fabricate high-performance MWCNT-based photovoltaics. We have thoroughly investigated the effect of different parameters, such as the total defect density of the absorber, the thickness of the MWCNTs film, the thickness of the absorber, shunt resistance, series resistance, and temperature, utilizing numerical simulations. By using the thin film photovoltaic program SCAPS-1D, we were able to simulate defect states and interfaces between layers to get as close as possible to a realistic PSC in our simulations and analysis. An optimized PSC of F-doped tin oxide (FTO)/titanium dioxide (TiO 2)/MAPbI 3 /MWCNTs/gold (Au) is designed here with a voltage-open circuit (V OC) of 1.100 V, a short-current density (J SC) of 19.192 mA/cm2, and efficiency of 18.3% with a high fill factor (FF) of 86.62%, which is among the best for carbon-based OHPSCs. • Carbon nanotube film was used as a hole transport layer in the OPSC. • A comparative study was performed between experimental and simulated MWCNT-based OPSCs. • The SCAPS-1D tool was used to numerically analyze the performance of MWCNT-based OPSCs. • An optimized device of FTO/TiO 2 /MAPbI 3 /MWCNTs/Au achieved an efficiency of 18.3% with an impressive FF of 86.62%. [ABSTRACT FROM AUTHOR]