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Perovskite solar cells (PSCs) have acquired popularity owing to their high efficiency, ease of fabrication, and affordability. In this context, the development of electron transport layers (ETLs) for highly efficient planar photovoltaic devices has received considerable attention. This study investigates the potential of zinc‐tin‐based ternary metal oxide ETLs for application in planar PSCs. Solution‐processed methods are used to fabricate crystalline zinc stannate (Zn2SnO4), amorphous zinc‐tin oxide (ZTO), and Zn2SnO4/ZTO‐based bilayer films, and their structural, morphological, and optoelectronic properties are thoroughly studied. X‐ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images show enhanced crystallite size and better surface morphology of perovskite films deposited on bilayer ETL. Photoluminescence (PL) studies and Hall effect measurements reveal superior charge extraction, improved charge carrier mobility (21.84 cm2 V−1 s−1) and enhanced n‐type conductivity in the bilayer ETL. Moreover, contact angle analysis of perovskite layer deposited on bilayer ETL shows increased resistance to moisture erosion (52.20°), which is particularly significant given the detrimental effects moisture can have on the performance of PSCs. [ABSTRACT FROM AUTHOR]

Carbazole‐derived self‐assembled monolayers (SAMs) with excellent hole‐extraction and injection properties are promising hole‐transporting materials for perovskite optoelectronic devices, including perovskite solar cells (PSCs) and perovskite light‐emitting diodes (PeLEDs). The performance and thermal stability of these SAMs are heavily influenced by their chemical structure. Herein, the construction of fused carbazole‐based SAMs is proposed by expanding the π‐conjugation of the carbazole unit for application in PSCs and PeLEDs. Three proof‐of‐concept SAMs are designed and synthesized, termed XS8, XS9, and XS10, that feature highly rigid and planar fused carbazole as the donor and a conjugated alkene unit as the linker. This conjugated extension improves planarity, stability, and enhances the molecular dipole moment. Among these, XS10, with the highest degree of conjugation, demonstrated superior performance in perovskite‐based devices. The PSC device utilizing XS10 achieves a maximum power conversion efficiency (PCE) of 20.28%, surpassing the 17.19% PCE of the classic 2PACz‐based device. Similarly, the PeLED device with XS10 achieves a maximum external quantum efficiency (EQE) of 16.6%, compared to 14.5% for PEDOT‐based devices. This work provides a novel molecular design strategy for creating efficient and stable SAMs for perovskite optoelectronics and other organic electronic devices. [ABSTRACT FROM AUTHOR]

Indium tin oxide (ITO) is the leading transparent electrode material in displays and in photovoltaics. As both these markets are vast and rapidly expanding, the demand for alternative transparent conductive oxides (TCOs) is becoming increasingly urgent due to the limited availability of indium. Herein, aluminum‐doped zinc oxide (AZO) is revisited as a promising indium‐free TCO candidate. An industrial‐scale pulsed laser deposition (PLD) process is developed that produces highly conductive and transparent AZO films at room temperature, without the need for post‐deposition annealing. This PLD‐AZO films have excellent morphological, electrical, and optical properties, with sheet resistances of ≈ 55–25 Ω ϒ−1 for thin TCO thicknesses (around 100 to 200 nm, respectively), and absorptance from 400 to 1000 nm below 10%. We demonstrate the application of this highly conductive PLD‐AZO not only as a bottom contact but also as an effective top contact in perovskite solar cells, highlighting its versatility. The AZO‐based devices achieve performance and stabilities equivalent to that of ITO‐based. This findings demonstrate the robustness and potential of PLD‐deposited AZO layers in enhancing displays and PV production and facilitating the wider adoption of renewable and sustainable TCO alternatives in the expanding photovoltaics and displays markets. [ABSTRACT FROM AUTHOR]

A novel cooperative regulatory strategy is proposed in this work to optimize the crystallization dynamics of Formamidinium (FA)‐based perovskite materials, which is achieved by meticulously incorporating the organic molecule guanidinium (GA+) and the high boiling point organic solvents N‐Methyl‐2‐Pyrrolidone (NMP) into the perovskite precursor solution synergistically. This findings indicated that the GA+ doping strategy (G‐DS) is toward to inhibits the formation of α‐phase perovskite crystals owing to its larger ionic radius, thereby promoting the formation of perovskite films with enlarged grain size. Simultaneously, the NMP‐doping strategy (N‐DS) has assisted controllable crystallization dynamics in as‐cast films by optimizing nucleation density and crystal growth rate through a delayed supersaturated environment induced re‐dissolution function. Briefly, it can assume that the crystallization dynamics dual modulation strategy enables the realization of high‐quality perovskite film with micro‐meter sized perovskite grain, appropriate internal strain and a compact, dense surface texture. The optimized films therefore exhibits powerful exciton separation energy, suppressed charge carrier recombination and reduces series resistance, leading to a remarkable champion power conversion efficiency (PCE) of 25.38% and exceptional reliability, retaining 93.09% of their initial PCE after storage the unencapsulated devices in a moisture‐rich environment for 2160 h. [ABSTRACT FROM AUTHOR]

Unlike traditional multi‐step synthetic approaches, we developed a single‐step synthesis of versatile π‐conjugated building blocks bearing post‐functionalizable C−H and C−Br bonds. Direct C−H arylation of 3‐bromothiophene with various iodo(hetero)aryls was successfully carried out with good regio‐ and chemo‐selectivity. Under optimized reaction conditions, 20 new compounds were facilely prepared in yields up to 91 %. One of the obtained compounds was demonstrated to further extend its conjugation length using a succinct synthetic plan to create two symmetrical oligo(hetero)aryls (MLC01 and MLC02) that were fabricated as effective hole‐transporting materials (HTM) for perovskite solar cells (PSC). PSC devices utilizing MLC01 as hole‐transport layer displayed promising power conversion efficiencies of up to 17.01 %. [ABSTRACT FROM AUTHOR]

Electron transport layer has always played a crucial role in the performance of the perovskite solar cells (PSCs). Particularly, SnO 2 -based PSC has sparked considerable interest due to its superior properties. Even with such remarkable properties, certain challenges persist such as agglomeration of SnO 2 particles which can lead to interfacial defects and poor morphology. To solve this problem, Agmatine Sulfate (AGTS) has been introduced as an interfacial modification agent which with the help of its active functional group including amide (-NH 2) and hydroxyl (OH) has allowed to facilitate the interaction at the interface between SnO 2 and perovskite. The interaction facilitates the growth of perovskite crystals while tuning the energy levels which has boosted the charge transfer capability of the layer. All these improvements in the properties have led to enhanced power conversion efficiency (PCE) from 11.17 % to 15.20 % for the encapsulated device. Furthermore, the modification also improved the long-term stability of the device as the AGTS-modified devices retained 87 % of their performance at 15–25 °C with humidity levels between 10 and 20 % for over a period of 31 days. Finally, the devices prepared with the AGTS also showed repeatability in their performance while boosting the overall performance of carbon-based PSCs (C–PSCs) and indicating a novel approach to not only increase but also accelerate the commercialization of C-PSC. [ABSTRACT FROM AUTHOR]

Hole‐collecting monolayers have greatly advanced the development of positive‐intrinsic‐negative perovskite solar cells (p‐i‐n PSCs). To date, however, most of the anchoring groups in the reported monolayer materials are designed to bind to the transparent conductive oxide (TCO) surface, resulting in less availability for other functions such as tuning the wettability of the monolayer surface. In this work, we developed two anchorable molecules, 4PATTI‐C3 and 4PATTI‐C4, by employing a saddle‐like indole‐fused cyclooctatetraene as a π‐core with four phosphonic acid anchoring groups linked through propyl or butyl chains. Both molecules form monolayers on TCO substrates. Thanks to the saddle shape of a cyclooctatetraene skeleton, two of the four phosphonic acid anchoring groups were found to point upward, resulting in hydrophilic surfaces. Compared to the devices using 4PATTI‐C4 as the hole‐collecting monolayer, 4PATTI‐C3‐based devices exhibit a faster hole‐collection process, leading to higher power conversion efficiencies of up to 21.7 % and 21.4 % for a mini‐cell (0.1 cm2) and a mini‐module (1.62 cm2), respectively, together with good operational stability. This work represents how structural modification of multipodal molecules could substantially modulate the functions of the hole‐collecting monolayers after being adsorbed onto TCO substrates. [ABSTRACT FROM AUTHOR]

In this work, low‐cost and simple structure perovskite solar cells (PSCs) were fabricated using formamidinium lead iodide (FAPbI3) as the light absorber and reduced graphene oxide nanofibers (rGO NFs) as the counter electrode (CE). The FAPbI3 light absorber was prepared using a two‐step solution process, whereas the rGO NFs were synthesized through a simple electrospinning method. The as‐prepared FAPbI3 and rGO NFs were characterized by high‐resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X‐ray diffraction (XRD) pattern analysis. The surface morphology of the as‐prepared FAPbI3 and rGO NFs showed crystalline and bead‐free fiber structures, as confirmed by HRTEM and FESEM image analysis. The AFM topographical images of FAPbI3 and rGO NFs further reveal the crystalline and fiber structures. XRD pattern analysis confirmed the cubic crystalline phase of FAPbI3 and the graphitic nature of rGO NFs. From the electrochemical impedance spectroscopy studies, the PSC assembled with the FAPbI3 light absorber and rGO NFs‐based CE demonstrated an electrical conductivity of 3.64 × 10−4 S cm−1. The fabricated PSC device achieved an efficiency of 8.78% compared to the 7.49% efficiency of the device with a sputtered gold CE. This work uniquely integrates advanced materials, cost‐effective manufacturing, and enhanced efficiency in PSCs using FAPbI3 light absorbers and rGO NFs, addressing key challenges in cost and sustainability in solar technology. [ABSTRACT FROM AUTHOR]

Perovskite tandem solar cells on textured silicon hold potential for surpassing single‐junction limits and industrial compatibility. However, integrating hole‐transporting layers (HTLs) onto textured silicon poses challenges in conformal coating, low‐temperature fabrication, and perovskite solution process compatibility. Here, an atomic layer deposition (ALD) copper‐doping process is introduced to fabricate low‐temperature NiOx HTLs (ALD Cu:NiOx), tailored for textured tandems. Copper‐doping reduces hydroxyl group content and Ni3+ defects, addressing the challenge of enhancing hole conductivity while mitigating recombination loss. This advancement enables to lower the post‐annealing temperature from >300 to 200 °C, achieving compatibility with silicon heterojunction (SHJ) cells and boosting the power‐conversion efficiency (PCE) of 1.65‐eV p–i–n perovskite solar cells to 22.47%. Integrating ALD Cu:NiOx beneath conventional self‐assembled monolayer HTL on textured SHJ leads to notable PCE enhancements, from 28.6% to 30.5% for 1‐cm2 tandems (certified stabilized PCE of 30.04%) and from 23.9% to 26.4% for 8.89‐cm2 tandems. Following 1000 h of maximum‐power‐point (MPP) tracking, tandems maintain 95% of initial efficiency. Notably, losses in open‐circuit voltage and PCE due to area upscaling reduced by over 20%, attributed to ALD Cu:NiOx's ability to enhance perovskite film wettability and minimize shunting on silicon pyramid texture, underscoring its impacts for textured tandem upscaling. [ABSTRACT FROM AUTHOR]

The halide perovskites have received extensive experimental and theoretical research interests for photovoltaic application. Most of the theoretical research is based on either material or device modeling approaches. However, literature is still deprived of studies based on the combination of these approaches, which are expected to yield predictions with superior accuracy. This report combines the first‐principles density functional theory (DFT) computations and device modeling to understand the impact of structural strain, generally induced during the crystallization phase of perovskite materials, on the photovoltaic performance of methyl ammonium lead halide (CH3NH3PbI3 or MAPbI3) based solar cell. The magnitude of strain varies in the range from +2% (tensile) to −2% (compressive). The impact of strain is analyzed in terms of the variations in band structure and values of optoelectronic parameters obtained using DFT calculations and further, their impact on performance metrics of solar cells is predicted using device simulations. The optimized cell efficiency under strain‐free conditions is 13% while it deteriorated to 1.6% under +2% tensile strain and improved to 22.3% under compressive strain. The simulation results underline the importance of engineering the structural strain during the crystallization of perovskite absorber material to achieve solar photovoltaic cells of high efficiency. [ABSTRACT FROM AUTHOR]

In recent years, third-generation solar cells have experienced a remarkable growth in efficiency, making them a highly promising alternative energy solution. Currently, high-efficiency solar cells often use top electrodes fabricated by thermal evaporation, which rely on high-cost and high energy-consumption vacuum equipment, raising significant concerns for mass production. This study develops a method for fabricating silver electrodes using the screen-printing process, aiming to achieve solar cell production through an all-solution coating process. By selecting appropriate blocking-layer materials and optimizing the process, we have achieved device efficiencies for organic photovoltaics (OPVs) with screen-printed silver electrodes comparable to those with silver electrodes fabricated by thermal evaporation. Furthermore, we developed a method to cure the silver ink using near-infrared (NIR) annealing, significantly reducing the curing time from 30 min with hot air annealing to just 5 s. Additionally, by employing sheet-to-sheet (S2S) slot-die coating, we scaled up the device area and completed module development, successfully verifying stability in ambient air. We have also extended the application of screen-printed silver electrodes to perovskite solar cells (PSCs). [ABSTRACT FROM AUTHOR]

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Using a one-dimensional solar cell capacitance simulator (SCAPS-1D), the initial simulation study is carried out by using inorganic Pb-free RbGeI3-based perovskite layer along with 2,2′,7,7′- tetrakis [N, N-di4-methoxyphenylamino]-9,9′-spirobifluorene (Spiro-OMeTAD) as a hole transport layer (HTL) and titanium dioxide (TiO2) as an electron transport layer (ETL), which shows a device efficiency of 13.11%. In addition, we investigated the impact of the conduction band offset (CBO) between the ETL and absorber layer, and the valence band offset (VBO) between the absorber and HTL. Band offsets play a critical role in carrier recombination at the interfaces, which determines the open-circuit voltage (Voc). Our study found that extremely negative and positive band offsets lead to reduced PV performance. The optimum position of CBO with respect to the perovskite layer is found to be − 0.2 to − 0.1 eV, while the optimum position of VBO is found to be − 0.1 to 0.0 eV. When ETL is replaced by ZnSe and HTL by CuSCN, the device shows an improved power conversion efficiency (PCE) of 15.82%, as predicted by band offset engineering. The effect of thickness and defect density of perovskite layer, back contact work function, series resistance, shunt resistance, and temperature on the performance of perovskite solar cell (PSC) has been analyzed. The optimized device exhibited a PCE of 17.93%, fill factor (FF) of 74.96%. Thus, the proposed simulation study promotes RbGeI3 as a promising candidate for the absorbing layer and provides significant insight that will help to find out the suitable ETL and HTL combination. [ABSTRACT FROM AUTHOR]

The non‐wetting issue of the self‐assembled monolayer (SAM) layer can complicate subsequent perovskite deposition and impact device efficiency. This study addresses this challenge using a dual approach involving co‐self‐assembly and a buffer layer to enhance the wettability and interfacial contact of the buried perovskite film. A weakly acidic boronic acid derivative, 4‐N, N‐dimethylbenzeneboronic acid hydrochloride (4NPBA), is used to co‐self‐assemble with the regular SAM molecule on ITO and the subsequent FAI buffer layer further increased perovskite film coverage to 89%. This dual buried interface strategy—SAM‐4NPBA/FAI—results in a flat and dense perovskite interface. The optimized device demonstrates a high fill factor of 88.35%, a power conversion efficiency of 25.29%, and retains over 99% of its initial efficiency after 500 h of maximum power point testing. [ABSTRACT FROM AUTHOR]

High‐quality and low‐defect perovskite active layer (PVK) and electron transport layer (ETL) are essential for high‐performance perovskite solar cells (PSCs). Herein, an alkylamine salt, cyclohexylmethylammonium chloride (CMACl) is introduced into tin oxide (SnO2) ETL. CMACl, possessing protonated −NH3+ group and Cl− ions, not only effectively inhibits the aggregation of SnO2 colloids and enhances the quality of the ETLs, but also reduces and passivates the defects on ETLs. On the other hand, via the across‐interface effect of alkylamine salt by thermal diffusion, the CMACl‐PbI2 intermediate phase is formed and leads to the high quality of PVK, meanwhile, the defect on the buried interfaces and in the bulk of PVK are passivated by CMA+ and Cl− ions. Consequently, the CMACl‐modified PSC achieves a preeminent power conversion efficiency of 25.47% and excellent stability. This work demonstrates a facile and effective approach for synchronous optimization of ETL and PVK for high‐performance PSCs by across‐interface effect. [ABSTRACT FROM AUTHOR]

Self‐healing transparent polymers are advantageous for various optoelectronic devices to improve resilience and durability. However, most of these materials have been applied only as flat films and do not address the need for optical structures that can manipulate light. Here optical microstructures embossed on a self‐healing polyurea film are presented which can autonomously recover from damage in ambient conditions. The polyurea film have a high optical transmittance above 90% and haze below 1.3%, and Young's modulus of 3.4 MPa. When applied as a protective light‐trapping layer for perovskite solar cells, the champion device shows improved short circuit current density from 23.7 to 25.0 mA·cm−2, and power conversion efficiency from 21.5% to 23.0%. Furthermore, the solar cell with the light‐trapping layer has improved impact resistance and can recover its performance after being scratched. It is envisioned that self‐healing optical structures can be realized for different geometries and materials in a range of optoelectronic applications to produce resilient and durable devices. [ABSTRACT FROM AUTHOR]

In this paper, the experimentally studied perovskite solar cell structure, ITO/SnO2/(FAPbI3) 1 − x (MAPbBr 3 − y Cly)x/Spiro-OMeTAD/Au, is considered as our primary cell structure. The Solar Cell Capacitance Simulator is used to investigate the cell performance. The cell performance is obtained after optimizing the influence of layer thickness (open circuit voltage = 1. 0 3 V, short circuit current = 2 5. 2 1 mA/cm2, fill factor = 6 5. 4 9 %, power conversion efficiency = 1 7. 0 2 %). In addition, various inorganic hole transporting layers are incorporated in place of Spiro-OMeTAD to improve cell stability and performance. Finally, with an open circuit voltage = 1. 1 3 V, a short circuit current = 2 7. 6 4 mA/cm2, a fill factor = 6 2. 1 5 %, and a power conversion efficiency = 19.55%, the optimized cell structure i.e., ITO/SnO2/(FAPbI3) 1 − x (MAPbBr 3 − y Cly)x/CulnSe2/Au, performs better. The cell performance is examined in relation to defect density in the absorber layer and at the layer interface. The primary cell results are also validated with the existing experimental results in the literature. This research will pave the way for the development of highly efficient mix-cation perovskite solar cells. [ABSTRACT FROM AUTHOR]

Developing cost-effective, high-efficiency, and stable hole transporting materials (HTMs) is crucial for replacing traditional spiro-OMeTAD in perovskite solar cells (PSCs) and achieving sustainable solar energy solutions. This work presents two novel air-stable HTMs based on a spiro[fluorene-9,9′-xanthene] (SFX) core functionalized with N-methylcarbazole (XC2-M) and N-hexylcarbazole (XC2-H) rings. These HTMs were synthesized via a straightforward, three-step process with good overall yields (∼40%) and low production costs. To further reduce device cost, carbon back electrodes were employed. The resulting PSCs, with a structure of FTO/SnO2/Cs0.05FA0.73MA0.22Pb(I0.77Br0.23)3/HTM/C achieved power conversion efficiencies (PCEs) of 13.5% (XC2-M) and 10.2% (XC2-H), comparable to the reference spiro-OMeTAD device (12.2%). The choice of alkyl chain on the HTM significantly impacts film morphology and device stability. The XC2-H device exhibited exceptional long-term stability, retaining approximately 90% of its initial PCE after 720 h of storage in 30–40% humidity air without encapsulation. This surpasses the performance of both the spiro-OMeTAD (55% retention) and XC2-M (68% retention) devices. The superior stability of XC2-H is attributed to its highly hydrophobic nature and the formation of a compact, smooth film due to interdigitation of the hexyl chains. The straightforward synthesis of XC2-H from commercially available materials offers a promising approach for large-scale PSC production. [ABSTRACT FROM AUTHOR]

The efficiency and stability of perovskite solar cells (PSCs) are influenced by various factors, such as controlling the migration of iodide anion (I−) and lithium cation (Li+), oxidizing the hole‐transport material of 2,2′,7,7′‐tetras(N,N‐p‐methoxyaniline)‐9,9′‐spirodifluorene (Spiro), and passivating the perovskite film. Herein, three multifunctional crown‐ether‐iodine (crown‐ether‐I2) supra‐molecules are investigated as activities in the hole transport layers (HTLs). Results indicate that the crown‐ether‐I2 can slowly release I2 to gently oxidize Spiro, and significantly improve the efficiency of PSCs. Moreover, the crown‐ether can contribute to stabilizing Li+ in HTL and passivating the defect sites on the upper interface of the perovskite layer, which can enhance the long‐term stability of PSCs. Furthermore, crown‐ether‐I2 can absorb I− to produce crown‐ether‐I3−, which can discharge I− to promote the self‐healing of I− defects and inhibit the migration of I− in the perovskite film, thereby further enhancing PSC's long‐term stability. PSC based on Dbenzo‐24‐Crown‐8‐Ether‐Iodine (DB24C8‐I2) achieves an impressive efficiency of 24.29%, which is much higher than that of the control device (22.28%). Additionally, the stability of the un‐encapsulated PSC with DB24C8‐I2 is significantly enhanced, while maintaining 96.9% of its original efficiency after 2000 h. This work provides an effective strategy for improving the efficiency and long‐term stability of PSCs. [ABSTRACT FROM AUTHOR]

The study synthesized triazine-based covalent organic framework (COF) materials (TPTP-COF, TPBT-COF, and TPBTz-COF) to be used as defect passivation additives in methylammonium lead iodide (MAPbI3)-based inverted perovskite solar cells (PVSCs). The frameworks of the COFs in the MAPbI3 layer can serve as a template for the crystal growth of perovskite, repairing crystal defects, enhancing the quality of the crystal film, and stabilizing perovskite materials. In addition to the conjugation intensity of the COFs, the average particle size of the COF in the precursor solution of the perovskite significantly influences the morphology, optical properties, and photovoltaic characteristics of the COF/MAPbI3 blend films used in PVCs. The crystal grain size, X-ray diffraction intensity, PL intensity, carrier lifetime, and charge mobility were improved in the MAPbI3 films when the COF was incorporated, particularly with the TPBTz-COF, compared to the original MAPbI3 film. The photovoltaic performance and stability of the PVSCs containing the COF were enhanced compared to the PVSCs based on pristine MAPbI3. The structure of the inverted PVSCs included indium tin oxide/NiOx/COF (TPTP-COF, TPBT-COF, or TPBTz-COF):MAPbI3/PC61BM/bathocuproine/Ag. TPBTz-COF exhibited the highest power conversion efficiency (PCE) among the COF additives, achieving a PCE of 20.04%, an open-circuit voltage of 1.04 V, a short-circuit current density of 24.26 mA cm–1, and a fill factor of 79.40%. The TPBTz-COF-based PVSC maintained 80% of its original power conversion efficiency after being stored for 400 h under ambient conditions (30 °C; 60% relative humidity). [ABSTRACT FROM AUTHOR]

Achieving high-performance perovskite solar cells with satisfactory efficiency requires a decrease of charge carrier recombination and intrinsic density of defects in organic and inorganic halide perovskite absorber materials. In this study, the effect of vanadium copper sulfide (VCuS) nanoparticles (NPs) used to accelerate CH3NH3PbI3 perovskite crystallization in a single phase is investigated. The results indicate that the employed VCuS NPs influence the purity, formation of a single phase, and crystallinity of CH3NH3PbI3 perovskite with favorable crystal growth in the (110) direction. The morphological analysis indicates the existence of a dense, compact, and homogeneous structure, which is associated with a large grain size that extends the lifetime and reduces recombination by increasing the electron-hole diffusion length. According to its optical characteristics, perovskite has an energy gap between 1.62 and 1.6 eV for visible light and an absorption coefficient in excess of 105 cm− 1. Photoluminescence (PL) measurements revealed that when VCuS NPs were added to perovskite thin films, the PL intensity decreased, indicating a decrease in charge recombination. For sample 8 mg/mL-VCuS, the bulk heterojunction solar cells demonstrated a power conversion efficiency (PCE) of 15.11%, a short-circuit current density (Jsc) of 20.93 mA/cm2, an open-circuit voltage (Voc) of 1.043 V, and a fill factor (FF) of 69.23%. In addition to enhancing light harvesting efficiency, this superior doped perovskite film eliminates pinholes, which reduces charge recombination in solar cells. Highlights: Treatment of CH3NH3PbI3 perovskite layers with VCuS NPs to improve PSCs. VCuS NPs doping treatment deeply enhances the purity, formation of a single phase, morphology, and crystallinity of CH3NH3PbI3 perovskite. JSC, VOC, and FF changed depending on the concentration of VCuS NPs used. A sample of an 8 mg/mL-VCuS -based solar cell device exhibited PCEs of 15.11%. [ABSTRACT FROM AUTHOR]

A back-contact perovskite solar cell (BC-PSC) has been simulated. The J–V curves were calculated with different degrees of the interfacial recombination, and the characteristics of basic physical phenomena inside the device, including carrier concentration distribution, ion concentration distribution, electric potential change, and carrier recombination rate, have also been investigated. It was found that the effect of the perovskite layer's upper surface (US) interfacial recombination on the hysteresis phenomenon is greater than that of the perovskite layer's lower surface (LS) interfacial recombination. In addition, it has been found that the inverted hysteresis phenomenon occurs in the BC-PSC with the LS interfacial recombination. Moreover, the hysteresis loops corresponding to the US interfacial recombination of the perovskite layer were close to the short-circuit current side, and the hysteresis loops corresponding to the LS interfacial recombination of the perovskite layer were close to the open-circuit voltage side. These results indicate that both of the US and LS interface recombinations in the BC-PSC play a crucial role in the hysteresis phenomenon. [ABSTRACT FROM AUTHOR]

Metal phthalocyanine (MPc) and naphthalocyanine (MNc) as hole-transport materials have the advantage of applying perovskite solar cells with excellent chemical stability. The purpose of this study is to fabricate and characterize perovskite solar cells using MPc and MNc as hole-transporting layers to improve their photovoltaic performance and stability. The effects of MPc and MNc on the photovoltaic properties and stability, crystallinity, surface morphology, and electronic structures have been investigated. The incorporation of nickel phthalocyanine (NiPc) as surface passivation supported the crystal growth and uniform film formation in the perovskite layer, yielding stability of performance. The photovoltaic mechanism has been discussed with the energy diagram of perovskite solar cells using an NiPc layer. The insertion of NiPc optimized the energy levels near the highest occupied molecular orbital while adjusting the valence band levels of the perovskite crystals, supporting charge-transfer from the perovskite crystal to the hole-transporting layer. [ABSTRACT FROM AUTHOR]

In recent perovskite solar cell (PSC) research, copper(I) thiocyanate (CuSCN) is an emerging inorganic hole transport layer (HTL) due to its suitable band gap, matched band edge positions with the perovskite and high stability under ambient conditions. However, being a coordination polymer typically requires sulfide‐based solvents that strongly interact with Cu(I) for dissolution. Dipropyl sulfide (DPS) is generally used where it is very sparingly soluble of about 10–12 mg mL−1, which leads to low surface coverage with pin‐holes on the surface responsible for the generation of defects at the perovskite–HTL interface. In this study, addition of the optimized amount 100 μL of co‐solvent Acetonitrile (ACN) increased the CuSCN dissolution from 10 to 35 mg mL−1. ACN can act as a Lewis‐base making it capable of donating electrons to a Lewis‐acid like Cu+ from CuSCN. ACN is a polar aprotic solvent due to its highly polar CN bond and by adding CuSCN the dipole–dipole interactions can stabilize the CuSCN molecules in solution. The device with architecture (FTO/c‐TiO2/mp‐TiO2/MAPbI3/CuSCN/carbon) showed the higher power conversion efficiency (PCE) of ≈11% with Voc of 1.01 V and Isc 24.65 mA cm−2 showing excellent stability stored under ambient atmosphere which retains 80% of its initial efficiency after 10 days. [ABSTRACT FROM AUTHOR]

The commonly used hole transport layer (HTL) Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) still has some shortcomings that will limit the development of Pb–Sn perovskite solar cells (PSCs). In this work, multifunctional ammonium sulfide (AS) is attempted to modify PEDOT:PSS/perovskite interface. AS has multiple effects on different functional layers and the device as a whole: a) optimize the perovskite crystallization by the formation of PbS nucleation sites; b) neutralize the acidity of PEDOT:PSS by reaction with PSS; c) promote carrier transport at HTL/perovskite interface by tuning the energy level of PEDOT:PSS. As a result, a power conversion efficiency of 24.23% is obtained in the reverse scanning direction and 23.84% in the steady‐state output power test for the single‐junction Pb–Sn PSCs, and 27.48% for all‐perovskite tandem solar cells. These results show that AS modification can be an effective way to boost the development of Pb–Sn PSCs. [ABSTRACT FROM AUTHOR]

UV radiation presents a substantial challenge to the stability of perovskite solar cells (PSCs), limiting their applications in harsh environments such as outer space. Herein, UV‐resistant molecule octinoxate (OCT) is introduced to mitigate the adverse effects of UV irradiation. OCT additive demonstrates the capability to modulate the crystallization process, resulting in perovskite films with larger grains and enhanced crystallinity. Moreover, OCT doping also facilitates charge extraction in PSCs. The PSCs with OCT doping exhibit an enhanced efficiency, increasing from 22.46% to 24.64%, along with improved stability with a T85 of 1000 h under continuous light exposure. Functioning as a sunscreen material, OCT mitigates UV‐induced degradation by absorbing irradiation and hindering I2 escape. Even after continuous exposure to 18.7 kWh m−2 UV illumination, the OCT‐doped PSCs maintain over 92% of their initial efficiency, meeting the 15 kWh m−2 UV exposure requirement specified in the IEC:61215 PV robustness testing standard. This study offers a straightforward approach to enhance the durability of PSCs under UV radiation, opening avenues for their application in extreme environments. [ABSTRACT FROM AUTHOR]

Effectively suppressing nonradiative recombination at the SnO2/perovskite interface is imperative for perovskite solar cells. Although the capabilities of alkali salts at the SnO2/perovskite interface have been acknowledged, the effects and optimal selection of alkali metal cations remain poorly understood. Herein, a novel approach for obtaining the optimal alkali metal cation (A‐cation) at the interface is investigated by comparatively analyzing different alkali carbonates (A2CO3; Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3). Theoretical calculations demonstrate that A2CO3 coordinates with undercoordinated Sn and O on the surface, effectively mitigating oxygen vacancy (VO) defects with increasing A‐cation size, whereas Cs2CO3 exhibits diminished preferability owing to enhanced steric hindrance. The experimental results highlight the crucial role of Rb2CO3 in actively passivating VO defects, forming a robust bond with SnO2, and facilitating Rb+ diffusion into the perovskite layer, thereby enhancing charge extraction, alleviating deep‐level trap states and structural distortion in the perovskite film, and significantly suppressing nonradiative recombination. X‐ray absorption spectroscopy analyses further reveal the effect of Rb2CO3 on the local structure of the perovskite film. Consequently, a Rb2CO3‐treated device with aperture area of 0.14 cm2 achieves a notable efficiency of 22.10%, showing improved stability compared to the 20.11% achieved for the control device. [ABSTRACT FROM AUTHOR]

Flexible perovskite solar cells (f‐PSCs) have drawn widespread interest owing to their distinguished advantages in excellent flexibility and relatively low cost. However, the brittle grain boundaries (GBs) and defects in flexible perovskite film tremendously influence the power conversion efficiency (PCE) and mechanical flexibility of f‐PSCs. Herein, photothermal welding, a novel method, is used to improve the perovskite films quality and the PCE of f‐PSCs with a near‐infrared (NIR) dye (indocyanine green, ICG) and polycaprolactone (PCL) as additives. Due to the strong photothermal effect, ICG molecule not only can significantly enhance NIR light harvesting, but it also can weld GBs upon exposure to an NIR laser, which is conducive to the GBs connections and device flexibility. Meanwhile, the S═O bond of ICG and C═O bond of PCL can simultaneously coordinate with Pb2+ defects in perovskite. Furthermore, they can control crystal growth to form a smooth surface of perovskite film. Consequently, the unencapsulated PSCs based on ICG/PCL displays a high champion PCE of 20.62%, with 88.4% of the original PCE after being placed in dark conditions for 600 h. The f‐PSCs delivers a champion PCE of 19.55% and exhibits excellent mechanical stability, thus providing a meaningful scientific direction to fabricate high‐flexible f‐PSCs. [ABSTRACT FROM AUTHOR]

A two‐dimensional (2D) conjugated microporous polymer with a structure of 2D nanosheets has been synthesized. Theoretical calculations and experimental results reveal that the Fermi level of this 2D polymer aligns well with perovskite absorber, and its conduction band is high enough to block electron transport into the anode. This 2D polymer is used to modify the hole transport layer, significantly improving its photoelectric properties, including enhanced hole mobility, matched energy level, and reduced recombination. Furthermore, the 2D polymer exhibits a mesoporous structure, allowing perovskite to fill into its loose framework, increasing the hole export area and providing a large hole transport flux. As a result, the efficiency of inverted perovskite solar cells enhances to 24.64 % from 21.17 % of control device without 2D conjugated microporous polymer. Given that this material can be synthesized on a large scale, this work has significant implications for the future development of 2D polymers in perovskite solar cells, potentially accelerating industrialization. [ABSTRACT FROM AUTHOR]

Copper(I) thiocyanate (CuSCN) is considered an efficient HTL of low cost and with high stability in perovskite solar cells (PSCs). However, the diethyl sulfide solvent used for CuSCN preparation is known to cause damage to the underlying perovskite layer in n-i-p PSCs. Antisolvent treatment of CuSCN during spin-coating can effectively minimize interfacial interactions. However, the effects of antisolvent treatment are not sufficiently understood. In this study, the effects of five different antisolvents were investigated. Scanning electron microscopy and X-ray diffraction analyses showed that the antisolvent treatment improved the crystallinity of the CuSCN layer on the perovskite layer and reduced damage to the perovskite layer. However, X-ray and ultraviolet photoelectron spectroscopy analyses showed that antisolvent treatment did not affect the chemical bonds or electronic structures of CuSCN. As a result, the power conversion efficiency of the PSCs was increased from 14.72% for untreated CuSCN to 15.86% for ethyl-acetate-treated CuSCN. [ABSTRACT FROM AUTHOR]

The performance of perovskite solar cells (PSCs) is often constrained by significant open‐circuit voltage (VOC) losses attributed to non‐radiative recombination processes induced by detrimental trap states. Surface treatments using passivating ligands typically involve single active binding sites on perovskite, posing challenges for effective passivation. Here, an aromatic donor‐acceptor (D‐A) configured phthalocyanine treatment is proposed to aim at dual‐site passivation of uncoordinated lead ions and effective mitigation of shallow and deep‐level defects on the perovskite surface. The resulting benign p‐type surface facilitates a more favorable energy level alignment and reduces energetic mismatches at the perovskite/Spiro‐OMeTAD interface. Pc‐BTBC, with its aromatic D‐A configuration, demonstrated compatibility with various perovskite compositions. Optimized PSCs achieves a power conversion efficiency (PCE) of 25.15% and reduces the VOC deficit to 0.379 V. Furthermore, encapsulated devices exhibited enhanced stability under damp‐heat conditions (ISOS‐D‐2, 50% RH, 65°C) with a T92 of 1000 h and maintained maximum power point tracking under continuous light in ambient air at 65°C (ISOS‐L‐2). Notably, fabricated wide‐bandgap semitransparent PSCs (ST‐PSCs) achieved a PCE of 20.29%, while four‐terminal perovskite/silicon tandem solar cells (4T‐P/STSCs) demonstrated an efficiency of 29.38%. This study provides insights into minimizing VOC losses and represents significant progress toward commercializing perovskite photovoltaics. [ABSTRACT FROM AUTHOR]

Crystalline quality is paramount for the performance and stability of perovskite films and devices. By regulating the nucleation and growth processes, it is possible to significantly enhance the crystalline quality. This work introduces a bidirectional synergistic crystallization strategy (BSC strategy) that synchronizes the crystallization kinetics across both the top and bottom surfaces of the perovskite film, thereby enhancing film quality and boosting the efficiency of perovskite solar cells (PSCs). Employing time‐resolved optical characterization techniques, it is demonstrated that the BSC strategy effectively mitigates the dissolution–recrystallization cycle of the perovskite nuclei and grains during annealing, accelerates the evaporation of residual solvents at the bottom of the perovskite film, and suppresses void formation at the buried interface. Depth‐resolved grazing‐incidence wide‐angle scattering analyses further confirm that the BSC strategy improves the crystalline quality of the perovskite film, promotes oriented growth, and minimizes internal residual strains caused by uneven growth dynamics. This approach results in a champion device efficiency of 24.98%, with the low voltage deficit of 360 mV. Moreover, device stability is markedly enhanced, after 1000 h of continuous light exposure, the efficiency remains over 91% of the initial value. [ABSTRACT FROM AUTHOR]

The buried interface between the electron transport layer (ETL) and the perovskite layer plays a crucial role in enhancing the power conversion efficiency (PCE) and stability of n–i–p type perovskite solar cells (PSCs). In this study, the interface between the chemical bath deposited (CBD) titanium oxide (TiO2) ETL and the perovskite layer using multi‐functional potassium trifluoromethyl sulfonate (SK) is modified. Structural and elemental analyses reveal that the trifluoromethyl sulfonate serves as a crosslinker between the TiO2 and the perovskite layer, thus improving the adhesion of the perovskite to the TiO2 ETL through strong bonding of the ─CF3 and ─SO3− terminal groups. Furthermore, the multi‐functional modifiers reduced interface defects and suppressed carrier recombination in the PSCs. Consequently, devices with a champion PCE of 25.22% and a fill factor (FF) close to 85% is achieved, marking the highest PCE and FF observed for PSCs based on CBD TiO2. The unencapsulated device maintained 81.3% of its initial PCE after operating for 1000 h. [ABSTRACT FROM AUTHOR]

The exceptional performance and potential of 2D/3D perovskites for enhancing the efficiency and stability of perovskite solar cells (PSCs) are extensively studied. However, selecting appropriate organic ligands is critical to this process. The incorporation of suitable ligands into the 2D layer can passivate surface defects, regulate energy level alignment, and significantly improve device stability. Conversely, using unsuitable ligands not only fails to achieve the desired functions, but also negatively impacts device efficiency by hindering charge carrier transport and causing energy level mismatch issues. Therefore, exploring the selection of organic ligands based on different requirements is essential. In this review, recent studies are classified based on the chemical structure of organic ligands, analyze their application requirements, and provide suggestions for choosing optimal organic ligands to construct 2D/3D perovskites. Additionally, the feasibility and necessity of utilizing more efficient organic ligands while providing guidance for future research on 2D/3D PSCs are emphasized. [ABSTRACT FROM AUTHOR]

Traditionally used phenylethylamine iodide (PEAI) and its derivatives, such as ortho‐fluorine o‐F‐PEAI, in interfacial modification, are beneficial for perovskite solar cell (PSC) efficiency but vulnerable to heat stability above 85 °C due to ion migration. To address this issue, we propose a composite interface modification layer incorporating the discotic liquid crystal 2,3,6,7,10,11‐hexa(pentoxy)triphenylene (HAT5) into o‐F‐PEAI. The triphenyl core in HAT5 promotes π–π stacking self‐assembly and enhances its interaction with o‐F‐PEAI, forming an oriented columnar phase that improves hole extraction along the one‐dimensional direction. HAT5 repairs structural defects in the interfacial layer and retains the layered structure to inhibit ion migration under heating. Ultimately, our approach increases the efficiency of solar cells from 23.36 % to 25.02 %. The thermal stability of the devices retains 80.1 % of their initial efficiency after aging at 85 °C for 1008 hours without encapsulation. Moreover, the optimized PSCs maintained 82.4 % of the initial efficiency after aging under one sunlight exposure for 1008 hours. This work provides a simple yet effective strategy using composite materials for interface modification to enhance the thermal and light stability of semiconductor devices. [ABSTRACT FROM AUTHOR]

Two new p‐type molecules, namely TAT‐TY3 and TAT‐TY4, featuring triazatruxene endcaps and carbazole π‐bridges, were synthesized. The photophysical and electrochemical properties of synthesized materials were comparatively investigated based on their 2,7‐ and 3,6‐carbazole conjugation pathways. Optical characterizations revealed the impact of non‐bonding electron delocalization of triazatruxene through carbazole moieties, resulting in a significant increase in absorption intensity corresponding to n‐π* energy transitions and a red shift of triazatruxene moieties. Consequently, the optical band gaps of TAT‐TY3 and TAT‐TY4 were measured at 3.0 and 3.2 eV, respectively. Moreover, the molecules′ first oxidation potentials exhibited a drastic difference due to the electrochemical behavior of 2,7‐ and 3,6‐carbazole moieties. The highest occupied molecular orbital (HOMO) level for TAT‐TY3 was measured to be −5.02 eV, while for TAT‐TY4, it was measured as −4.67 eV. Hole‐extraction properties were explored using steady‐state and time‐resolved photoluminescence spectroscopy, revealing enhanced charge transfer between the TAT‐TY3/Perovskite interface due to the better alignment of HOMO energy levels. The photovoltaic performances of the hole‐transporting materials (HTMs) were successfully characterized in triple‐cation perovskite solar cells and efficiencies of up to 17.9 %, 16.2 %, and 9.8 % were achieved for Spiro‐OMeTAD, TAT‐TY3, and TAT‐TY4, respectively. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) are considered the most promising photovoltaic devices to replace silicon-based solar cells because of their low preparation cost and high photoelectric conversion efficiency (PCE). Reducing defects in perovskite films is an effective means to improve the efficiency of PSCs. In this paper, a lead chelator was selected and mixed into hole transport layers (HTLs) to design and prepare mesoporous PSCs with the structure of ITO/PTAA(BCP)/Al2O3/PVK/PCBM/BCP/Ag, and its modification effect on the buried interface at the bottom of the perovskite layer in the mesoporous structure was explored. The experimental results show that in the presence of mesoporous alumina, the lead chelator can still play a role in modifying the bottom of the perovskite film. The use of lead chelator as passivation material added to the HTL can effectively reduce the residue of dimethyl sulfoxide (DMSO) and decrease the defects at the bottom of the perovskite film, which dramatically improves the device performance. The PCE of the device is increased from 18.03% to 20.78%, which is an increase of 15%. The work in this paper provides an effective method to enhance the performance of PSCs. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have gained popularity in recent times due to their high-power conversion efficiency (PCE) and cost-effective manufacturing. Heterojunction devices are emerging as an interesting topic for researchers. In this study, a comparison is made between the experimental performance and their numerical simulations using the solar cell capacitance simulator (SCAPS-1D) software of CsPbI3/CsPbBr3 perovskite bilayer and CsPbI3 single-layer perovskite solar cell. It is evident from the experimental results that the incorporation of CsPbBr3 layer enhances the PCE from 4.92 to 9.9% under solar illumination. Further, an ideally optimized device was made using SCAPS-1D by varying the thickness, defect density, back metal contact and temperature. The influence of series and shunt resistances (Rseries and Rshunt) was theoretically investigated and discussed using the SCAPS-1D program to model the electrical characteristics of the cell as a function of active layer composition. Without these parasitic resistances, the results of the ideal device do not resemble the experimentally calculated values. By feeding the experimentally calculated Rseries and Rshunt values to SCAPS-1D, we can analyse the primary constraints of the device's current voltage characteristics. Ultimately, it is established that the heterojunction device can help in enhancing the performance of PSCs. [ABSTRACT FROM AUTHOR]

In recent years, significant progress has been achieved in the field of perovskite solar cells (PSCs), particularly those comprised of organic–inorganic lead halides, resulting in a remarkable record efficiency of 25.20%. However, the persistent issue of lead toxicity poses a considerable barrier to their widespread commercial adoption. To address this challenge, this study focuses on the optimization of lead-free germanium-based halide PSCs using SCAPS-1D simulation software. In our investigation, CsGeI3 serves as the absorber layer, TiO2 functions as the electron transport layer (ETL), Cu2O is utilized as the hole transport layer (HTL), and various metals are employed as the back metal contact (BMC). The optimization of the BMC leads to the establishment of the FTO/TiO2/CsGeI3/Cu2O/Ni structure. Subsequent optimization steps include fine-tuning the thickness of the absorber, ETL, and HTL layers, as well as optimizing acceptor doping and defect density in the absorber and HTL layers. Sequentially, donor doping and defect density in the ETL are investigated. Interfacial defect densities, along with the impact of temperature, series resistance, and shunt resistance on the photovoltaic performance, are also considered. Upon completion of these optimization procedures, the final device exhibits notable performance characteristics, including an open-circuit voltage (VOC) of 1.165 V, fill factor (FF) of 88.52%, short-circuit current density (JSC) of 24.40 mA/cm2, and a power conversion efficiency (PCE) of 25.16%. Furthermore, the optimized structure without Cu2O HTL demonstrates impressive performance, yielding a PCE of 25.15%. The outcomes presented in this study hold promise for the development of advanced lead-free PSCs, paving the way for high conversion efficiencies in future solar energy technologies. [ABSTRACT FROM AUTHOR]

Abstract Developing cost-effective, high-efficiency, and stable hole transporting materials (HTMs) is crucial for replacing traditional spiro-OMeTAD in perovskite solar cells (PSCs) and achieving sustainable solar energy solutions. This work presents two novel air-stable HTMs based on a spiro[fluorene-9,9′-xanthene] (SFX) core functionalized with N-methylcarbazole (XC2-M) and N-hexylcarbazole (XC2-H) rings. These HTMs were synthesized via a straightforward, three-step process with good overall yields (∼40%) and low production costs. To further reduce device cost, carbon back electrodes were employed. The resulting PSCs, with a structure of FTO/SnO2/Cs0.05FA0.73MA0.22Pb(I0.77Br0.23)3/HTM/C achieved power conversion efficiencies (PCEs) of 13.5% (XC2-M) and 10.2% (XC2-H), comparable to the reference spiro-OMeTAD device (12.2%). The choice of alkyl chain on the HTM significantly impacts film morphology and device stability. The XC2-H device exhibited exceptional long-term stability, retaining approximately 90% of its initial PCE after 720 h of storage in 30–40% humidity air without encapsulation. This surpasses the performance of both the spiro-OMeTAD (55% retention) and XC2-M (68% retention) devices. The superior stability of XC2-H is attributed to its highly hydrophobic nature and the formation of a compact, smooth film due to interdigitation of the hexyl chains. The straightforward synthesis of XC2-H from commercially available materials offers a promising approach for large-scale PSC production.

Perovskite solar cells (PSCs) have gained a lot of attention due to their high efficiency and low cost. In this research paper, a methylammonium tin iodide (CH3NH3SnI3) based solar cell was simulated using a one-dimensional solar cell capacitance simulation (SCAPS-1D) tool. The SCAPS-1D tool is based on Poisson and the semiconductor equations. After thorough investigation, the initial device presents the following parameters; power conversion efficiency (PCE)=15.315%, fill factor (FF)=64.580%, current density (Jsc)=29.152 mA/cm2, and open circuit voltage (Voc)=0.813 V. The effect of absorber and ETL thicknesses were explored systematically. The performance of the simulated device was significantly influenced by the thickness of the absorber and ETL. The optimized absorber thickness was 0.5 µm and the ETL thickness was 0.02 µm, giving rise to an optimized PCE of 15.411%, FF of 63.525%, Jsc of 29.812 mA/cm2, and Voc of 0.814 V. Additionally, the effect of temperature on the optimized device was evaluated and found that it affects the performance of the device. This model shows the prospect of CH3NH3SnI3 as a perovskite material to produce toxic-free environment-friendly solar cells with high efficiency.

To date, the lead-free perovskite has shown remarkable progress in solar cell development owing to its outstanding properties. Here, we report on the structural, optical, and photovoltaic properties of methylammonium bismuth iodide ((CH3NH3)3Bi2I9, MBI) and cesium bismuth iodide (Cs3Bi2I9, CBI) hybrid perovskite solar cells (HPeSCs) fabricated using the hot immersion method (HIM) with changing the composition x, ((CH3NH3)1-xCsx)3Bi2I9; from x = 0 to x = 1.0. The compact MBI and CBI films were successfully fabricated on FTO glass substrates at x = 0 and x = 1, respectively. On the other hand, the CBI/MBI mixed structure with a rough surface was obtained in the range from x = 0.2 to x = 0.8. An incorporation of CBI in MBI showed improvement, especially in optical properties, indicating that the absorption region was extended toward a longer wavelength region with increasing x. Interestingly, the open-circuit voltage of the hybrid cell was higher than that of the MBI or CBI cell, whereas the short-circuit current was lower than that of the MBI or CBI cell. This work provides alternative ways to fabricate lead-free PeSCs using a simple and low-cost method in the future.

Abstract This article investigates the impact of metal-organic frameworks (MOFs) on the performance and stability of perovskite solar cells (PSCs), specifically focusing on the type of metal and the morphology of the MOF. Two types of MOFs, copper-benzene-1,3,5-tricarboxylate (Cu-BTC MOF) with spherical morphology and cobalt-benzene-1,3,5-tricarboxylate (Co-BTC MOF) with rod morphology, are synthesized and spin-coated on TiO2 substrates to form FTO/TiO2/MOF/CH3NH3PbI3/C-paste PSCs. The morphology and size of the MOFs are characterized by scanning electron microscopy (SEM), and the crystallinity and residual PbI2 of the perovskite films are analyzed by X-ray diffraction (XRD). The results show that the Co-BTC MOF PSC exhibits the highest power conversion efficiency (PCE) of 10.4% and the best stability, retaining 82% of its initial PCE after 264 h of storage in ambient air. The improved performance and stability are attributed to the enhanced crystallinity and reduced residual PbI2 of the perovskite film after Co-BTC MOF modification. The paper showcases the immense potential of MOF-based interlayers to revolutionize PSC technology, offering a path toward next-generation solar cells with enhanced performance and longevity.

Abstract The most rapidly expanding type of solar cells are the Perovskite Solar Cells (PSCs), because of its high device performance, ease of synthesis, high open-circuit voltage, and affordability. Despite these advantages, the development of perovskite-based solar cells continues to be impeded by the issues with perovskite stability and the utilization of the hazardous heavy element lead (Pb). The study emphasizes on the bifacial structure that maintains the conventional absorber layer and electron transport layer (ETL) in the optimized PSC structure. This study employs SCAPS software for device simulation to comprehensively analyze how various parameters affect the performance of solar cells. Additionally, doping concentration variation in both ETL and HTL are explored. The simulation reveals that changing device structure from monofacial to bifacial significantly influences PSC performance, demonstrating that optimizing individual layers effectively enhances overall solar cell performance. The optimized structure achieves impressive PSC performance metrics through parametric analysis, such as voltage (VOC) of 1.18 V, fill factor (FF) of 82.24%, current density (JSC) of 27.12 mA/cm2, power conversion efficiency (PCE) of 27.90% for an incident solar spectrum from the ETL side, and power conversion efficiency (PCE) of 19.86% for an incident solar spectrum from the HTL side, the calculated bifaciality factor (BF) for this structure is 71.18%.

Nitrogen‐rich heterocyclic frameworks have attracted enormous interest in organic chemistry and materials science. However, their potential for developing photoluminescent materials remains underexplored due to their relatively low molecular stabilities. In this work, two tricyclic fused nitrogen‐rich fluorescent heterocycles were synthesized and characterized. The photophysical properties of the synthesized 4 and 5 were investigated through theoretical and experimental studies. In addition, their physicochemical and energetic properties and the performance as an additive to the perovskite absorption layer of the perovskite solar cell were also studied. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) are considered to be a promising candidate for near‐space applications due to their high specific power, excellent radiation resistance, and compatibility with flexible substrates. Nevertheless, the low‐temperature cycles impose considerable challenges to their long‐term stability. Herein, the extremely low‐temperature photovoltaic process of PSCs is investigated and the effect mechanisms of PAN (Polyacrylonitrile) as an additive are revealed. It is found that the additive PAN regulates perovskite lattice stress and stabilizes perovskite lattice structure and thus retards perovskite phase transition at low temperatures. Moreover, the PAN improves perovskite dielectric properties and ion migration activation energy and effectively passivates perovskite defects at low temperatures. Therefore, the carrier transport/extraction/collection abilities at low temperatures are enhanced effectively by alleviating exciton effect and increasing dielectric screening effect. Benefiting from these positive effects of PAN, the PAN‐modified device achieves a maximum efficiency of 24.34% at 150K and maintains 72% of its initial value after 120 thermal cycles (290‐130K). Also, the PAN‐modified flexible devices exhibit excellent bending stability and thermal cycle stability. This study provides a deep insight into understanding the extremely low‐temperature photovoltaic behavior of PSCs and demonstrates the potentiality of PAN additive strategy for achieving efficient and stable PSCs at low temperatures. [ABSTRACT FROM AUTHOR]

Perovskite solar cells are among the most promising new solar technologies, already surpassing polycrystalline silicon solar cell efficiencies. The stability of the highest efficiency devices at elevated temperature is, however, poor. These cells typically use Spiro‐MeOTAD as the hole transporting layer. It is generally believed that additives, required for enhancing electrical conductivity and optimizing energy level alignment, are responsible for the reduced stability—inferring that Spiro‐MeOTAD based hole transporting layers are intrinsically unstable. Here, a reliable noble metal free synthesis of Spiro‐MeOTAD (bis(trifluoromethane)sulfonimide)4 is presented which is used as the oxidizing agent. No additives are added to the partially oxidized Spiro‐MeOTAD hole‐transporting layer. Device efficiencies up to 24.2% are achieved. Electrical conductivity is largely developed by the first 1% oxidation. Further oxidation shifts the energy levels away from the vacuum level, which allows tuning of the energy level alignment without the use of additives—contradicting the current understanding of this system. Without additives, devices demonstrate significant improvement in stability at elevated temperatures up to 85 °C under one sun over 1400 h continuous illumination. The remaining degradation is pinpointed to ion migration and reactions in the perovskite layer which may be further suppressed with compositional engineering and adequate ion barrier layers. [ABSTRACT FROM AUTHOR]

In this study, eutectic gallium–indium alloy (EGaIn) liquid metal is used as the rear electrode for perovskite solar cells (PSCs), where the interfacial properties of the device, particularly the beneficial roles of the surface oxide of the liquid metal, are explored. The findings demonstrate that the native oxide of the EGaIn electrode significantly affects the stability of photovoltaic performance and impedance characteristics including series and shunt resistances. Based on the results, the following hypothesis is formulated: the oxide interlayer serves two crucial functions of a barrier against metal diffusion and a tunnel for enhancing charge extraction and transfer. The results of elemental mapping and trap density calculation support the former function of the hypothesis that the oxide film can effectively prevent metal penetration into the perovskite layer. Furthermore, measurements involving capacitance−voltage and time‐resolved photoluminescence confirm that the oxide film on the liquid metal eliminates the interfacial Schottky barrier, promoting efficient charge extraction and transfer processes. Finally, the investigation is extended to develop flexible PSCs using the EGaIn electrode, which consistently exhibits stable performance during repeated bending cycles. Notably, the EGaIn rear electrode can be readily removed and collected through a straightforward acid treatment, offering a promising avenue for efficient cell recycling. [ABSTRACT FROM AUTHOR]

This paper discusses the invertible current–voltage characteristics of perovskite solar cells (PSCs). To that end, the well-known invertible analytical current–voltage dependencies expressed through the Lambert W function are analyzed and checked on three examples. It is concluded that the expression for voltage–current characteristics is not applicable for a whole voltage range (for no-load and low-load operation). Therefore, an analytical closed-form expression for PSC voltage–current characteristics is derived by using the g-function (or LogWright function). Second, a novel closed-form expression for the no-load voltage is derived. Third, a novel iterative procedure for solving the g-function is proposed. The proposed iterative procedure for solving g-functions, called g-IP, is independent of the initial conditions, unlike in the literature. Furthermore, for large values of the argument of the g-function, approximate solutions for g-function solving were derived and tested, especially for regions about the maximum power point. The proposed approach guarantees an accurate representation of the PSC voltage–current characteristics. Therefore, this paper represents unique research in the field of PSC modeling. [ABSTRACT FROM AUTHOR]