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In monolithic perovskite silicon dual‐junction solar cells, it is crucial that the subcells are current‐matched to maximize performance. The most precise method to determine the current (mis)match of a monolithic dual‐junction solar cell is a spectrometric measurement with, e.g., a light‐emitting diode (LED)‐based solar simulator. However, recoding multiple current voltage curves (IV curves) under different red‐ and blueshifted spectra relative to the AM1.5g reference spectrum is time‐consuming. Herein, a new method is suggested to quickly test solar cells for current mismatch. A solar simulator with two lasers instead of multiple LEDs is used, so that two monitor diodes can track intensity changes of each light source during the measurement. Postmeasurement corrections can be applied using this data, circumventing long stabilization times of the solar simulator. To minimize the scan time, it is focused only on determining the correct short‐circuit current and not the full IV curve. The measurement method is validated comparing it to conventional spectrometric measurements using a stable III–V monolithic dual‐junction solar cell. The measurement on the proof‐of‐concept setup shows a deviation of only 2.3% in the current at the current matching point compared to the reference measurement. [ABSTRACT FROM AUTHOR]

Aromatic linker‐constructed self‐assembled monolayers (Ar‐SAMs) with enlarged dipole moment can modulate the work function of indium tin oxide (ITO), thereby improving hole extraction/transport efficiency. However, the specific role of the aromatic linkers between the polycyclic head and the anchoring groups of SAMs in determining the performance of perovskite solar cells (PSCs) remains unclear. In this study, we developed a series of phenothiazine‐based Ar‐SAMs to investigate how different aromatic linkers could affect molecular stacking, the regulation of substrate work function, and charge carrier dynamics. When served as hole‐selective layers (HSLs) in PSCs and monolithic perovskite/silicon tandem solar cells (P/S‐TSCs), we found that the Ar‐SAM with naphthalene linker along the 2,6‐position axis (β‐Nap) could form dense and highly ordered HSLs, enhancing interfacial interactions and favoring optimal energy level alignment with the perovskite films. Using this strategy, the optimized wide‐band gap PSCs achieved an impressive power conversion efficiency (PCE) of 21.86 % with negligible hysteresis, utilizing a 1.68 eV perovskite. Additionally, the encapsulated devices demonstrated enhanced stability under damp‐heat conditions (ISOS‐D‐2, 50 % RH, 65 °C) with a T91 of 1000 hours. Notably, the fabricated P/S‐TSCs, based on solution‐processed micron‐scale textured silicon heterojunction (SHJ) solar cells, achieved an efficiency of 28.89 % while maintaining outstanding reproducibility. This strategy holds significant promise for developing aromatic linking groups to enhance the hole selectivity of SAMs. [ABSTRACT FROM AUTHOR]

The novel, high electron mobility material ZnOxNy${\rm ZnO}_x{\rm N}_y$ has been investigated theoretically as an absorber in a two‐terminal tandem solar cell. In addition to its high mobility, ZnOxNy${\rm ZnO}_x{\rm N}_y$ can attain sufficiently low carrier concentration to enable pn$pn$‐junctions, and has a tunable bandgap around the 1.7 eV range. It is therefore suitable for pairing with a Si‐based bottom cell. In addition to the ZnOxNy${\rm ZnO}_x{\rm N}_y$ layer, the tandem cell consists of a Cu2O${\rm Cu}_2{\rm O}$ emitter and a Si heterojunction bottom cell. A buffer layer is introduced between the emitter and absorber in the top cell to mediate a large valence band offset that resulted in a poor fill factor, FF$FF$. A ZnOxNy${\rm ZnO}_x{\rm N}_y$ buffer layer bandgap of 1.5 eV gave the highest power conversion efficiency (PCE). The objective is to estimate the optimal performance of ZnOxNy${\rm ZnO}_x{\rm N}_y$ in a tandem solar cell. The dependence of current–voltage (J$J$–V$V$) characteristics on thickness, mobility and carrier concentration in the ZnOxNy${\rm ZnO}_x{\rm N}_y$ layer is evaluated, and found to yield maximum performance with 0.35 μm$\umu {\rm m}$, 250 cm2${\rm cm}^2$ Vs–1 and 1016$10^{16}$cm−3${\rm cm}^{-3}$, respectively. Using these conditions, the J$J$–V$V$ parameters of the device under AM1.5 illumination are short circuit current density, JSC=17.76$J_{SC}=17.76$ mA cm−2${\mathrm{cm}}^{-2}$, open circuit voltage, VOC=1.74$V_{OC}=1.74$ V, FF=83.8%$FF=83.8\%$ and PCE=25.9%${\rm PCE}\,=25.9\%$. With this, it is reported on, to the best of the knowledge, the first device simulation based on ZnOxNy${\rm ZnO}_x{\rm N}_y$. [ABSTRACT FROM AUTHOR]

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One of the primary barriers to the advancement of high-efficiency energy conversion technologies is the Shockley–Queisser limit, which imposes a fundamental efficiency constraint on single-junction solar cells. The advent of multi-junction solar cells provides a formidable alternative to this obstacle. Among these, organic-inorganic perovskite solar cells (PSCs) have captured substantial interest due to their outstanding optoelectronic properties, including tunable bandgaps and high-power conversion efficiencies, positioning them as prime candidates for multi-junction photovoltaic systems. We give a review of the latest advancements in four-terminal (4T) perovskite tandem solar cells (TSCs), emphasizing four pertinent configurations: perovskite-silicon (PVK/Si), perovskite-perovskite (PVK/PVK), perovskite-Cu(In,Ga)Se2 (PVK/CIGS), and perovskite-organic (PVK/organic), as well as other emerging 4T perovskite TSCs. Further, it also emphasizes the advancement of semitransparent wide-bandgap PSCs for TSC applications, tackling important issues and outlining potential future directions for optimizing 4T tandem design performance.

Herein, we have explored the recombination dynamics and defect concentration of a mixed cation mixed halide perovskite Cs0.17FA0.83PbI1.8Br1.2 with 1.75 eV bandgap after exposure to a gamma-ray source (2.5 Gy/min). We used photoluminescent spectroscopy to observe changes in recombination dynamics on perovskite films, impedance spectroscopy to reveal the contribution of interface recombination, and admittance spectroscopy to define the activation energy and concentration of defects. It was revealed that moderate doses (up to 10 kGy) passivate defects with activation energy ≈ 0.5 eV and at the same time form new defects that cause dramatic growth of the diffusion coefficient and migration of mobile ions. These two processes with opposite direction result in high radiation tolerance of the studied material and solar cells up to 10 kGy. Doses above 10 kGy are detrimental for perovskite solar cells, mainly due to the growing role of interface recombination. The results encourage the use of the wide bandgap perovskite Cs0.17FA0.83PbI1.8Br1.2 as a material for tandem solar cells with potential applications in a space environment.

Wide‐bandgap (WBG) perovskite solar cells (PSCs) play a crucial role in advancing perovskite‐based tandem solar cells. In WBG perovskite films, grain boundary (GB) defects are the main contributors to open‐circuit voltage (VOC) deficits and performance degradation. This report presents an effective strategy for passivating GBs by incorporating an inorganic protective layer and reducing the density of GBs in perovskite films. This is achieved by integrating potassium thiocyanate (KSCN) into I‐Br mixed halide WBG perovskites. It is reported for the first time that the incorporation of KSCN creates band‐shaped barriers along the GBs. In addition, KSCN enlarges the grains of perovskite film. Elemental and structural analyses reveal that these barriers are composed of potassium lead halide. Incorporating KSCN significantly enhances the fill factor and VOC of WBG single‐junction PSCs by reducing trap density. This results in high power conversion efficiencies of 19.22% (bandgap of 1.82 eV), 20.45% (1.78 eV), and 21.54% (1.70 eV) with a C60/bathocuproine electron transport layer, and 18.51% (1.82 eV) with a C60/SnO2. Furthermore, both operational and shelf stabilities are significantly improved due to reduced light‐induced halide segregation. By using inorganic‐halide‐passivated WBG sub‐cells, a monolithic all‐perovskite tandem solar cell with an efficiency of 27.04% is demonstrated. [ABSTRACT FROM AUTHOR]

The use of carbazole‐based self‐assembled monolayer (SAM) as a hole transport layer (HTL) has led to the efficiency advancement in p–i–n perovskite solar cells (PSCs). However, PSCs with SAM HTL display a large spread in device performance even on small‐area substrates owing to poor SAM surface coverage and dewetting of the perovskite ink. Efforts to improve the uniformity in device performance of SAM‐based PSCs have been confined to spin‐coating method, which lacks high‐throughput capabilities and leads to excessive material wastage. Herein, a scalable bilayer HTL stack with sputtered NiO and blade‐coated SAM is utilized to achieve improved SAM coverage and accomplish uniform coating of perovskite absorber on 5 cm × 5 cm substrates. Fully scalable p–i–n PSCs with efficiency close to 19% with a minimal spread in device performance are achieved. To showcase the upscaling potential, near‐infrared‐transparent perovskite mini‐modules with efficiency close to 15% and 13% are achieved on an aperture area of 2.56 and 12.96 cm2. Together with low‐bandgap (1.0–1.1 eV) Cu(In,Ga)Se2 (CIGS) mini‐modules, the first fully scalable 4‐terminal perovskite‐CIGS tandem mini‐module with an efficiency of 20.5% and 16.9% on an aperture area of 2.03 and 10.23 cm2 is demonstrated. [ABSTRACT FROM AUTHOR]

Thin‐film tandem photovoltaic (PV) technology has emerged as a promising avenue to enhance power conversion efficiency beyond the radiative efficiency limit of single‐junction devices. Combining a tunable wide‐bandgap perovskite cell with a commercially established narrow‐bandgap cadmium selenium telluride (CdSeTe) cell in a comparatively easy‐to‐fabricate four‐terminal (4‐T) arrangement is a great step in that direction. Herein, the impact of the transparent back contact and the perovskite absorber bandgap on the performance of 4‐T perovskite–CdSeTe tandem solar cells is investigated. 4‐T perovskite–CdSeTe tandem device architecture with ≈25% efficiency is demonstrated and a feasible pathway is shown to improve the tandem efficiency to more than 30%. The results show that the integration of CdSeTe with perovskite in 4‐T tandem PV configurations represents a significant advancement toward achieving higher efficiency and low‐cost tandem PVs. [ABSTRACT FROM AUTHOR]

Lead-free hybrid organic–inorganic perovskite have gained remarkable interest for photovoltaic application due to their lack of toxicity. In this work, we design and simulate for the first all HTL-free non-toxic perovskite tandem solar device using SCAPS-1D. The (MAGeI3) with 1.9 eV band gap is employed as a top cell, while the bottom cell is FASnI3 with a band gap of 1.41 eV. The proposed tandem device is interesting since we remove the HTL layer from two sub-cells. Initially, individual sub-cell improvement was carried out through varying the solar cell's parameters, starting with the absorber thickness and doping level, ETL thickness and electron affinities of both sub-cells. The effects of capture cross section of ETL/absorber interface as well as various ETL on the performance of bottom sub-cell have been studied. The efficiency of the devices has been demonstrated to be affected by all these parameters. Then, the tandem solar cell is constructed using these individual HTL-free optimized sub-cells. A current matching JSC of 15.85/cm2 was produced between the top and bottom sub-cell thickness of 860 and 925 nm, respectively. The tandem device simulation with MAGeI3 on FASnI3 yielding a PCE of 25.69%, VOC = 1.3681 V; JSC = 15.85 mA/cm2, and FF = 75.95% was much greater than each sub-cells output. The findings of this study demonstrate the possibility of using cheap, HTL-free non-toxic perovskite solar cells to produce high PCE in tandem solar devices. [ABSTRACT FROM AUTHOR]

Developing tandem solar cells is an excellent strategy to break through the Shockley–Queisser (SQ) limit for single-junction solar cells. A major factor in developing a tandem solar cell is to make it cost-efficient with high device performance. Here, we demonstrate the proof of concept of four terminal (4T) tandem solar cell using a perovskite solar cell (PSC) as a wide bandgap (WBG) top cell and narrow bandgap (NBG) cadmium telluride (CdTe) as a bottom cell. A 4T tandem device power conversion efficiency (PCE) exceeding 23% was obtained using SCAPS (solar cell capacitance simulator) simulation, demonstrating the architecture's feasibility. Further, we fabricated two WBG semitransparent perovskite cells with different bandgaps (1.6eV and 1.77eV) and mechanically stacked it with NBG CdTe (1.5eV) to obtain tandem efficiencies of 18.2% and 19.4% respectively. From the results, we concluded that the PSC with a bandgap of 1.77eV is more suitable to be paired with the NBG CdTe solar cell to get good device performance and effective spectral utilization. The experimental results show promising device performance and pave the way to further improve device performance by engineering the device architecture and interfaces. [ABSTRACT FROM AUTHOR]

Sputtering nickel oxide (NiOx) is a production‐line‐compatible route for depositing hole transport layers (HTL) in perovskite/silicon tandem solar cells. However, this technique often results in films with low crystallinity and structural flaws, which can impair electronic conductivity. Additionally, the complex surface chemistry and inadequate Ni3+/Ni2+ ratio impede the effective binding of self‐assembled monolayers (SAMs), affecting hole extraction at the perovskite/HTL interface. Herein, these issues are addressed using a recrystallization strategy by treating sputtered NiOx thin films with sodium periodate (NaIO4), an industrially available oxidant. This treatment improved crystallinity and increased the Ni3+/Ni2+ ratio, resulting in a higher content of nickel oxyhydroxide. These enhancements strengthened the SAM's anchoring capability on NiOx and improved the hole extraction at the perovskite/HTL interface. Moreover, the NaIO4 treatment facilitated Na+ diffusion within the perovskite layer and minimized phase separation, thus improving device stability. As a result, single‐junction perovskite solar cells with a 1.68 eV bandgap achieve a power conversion efficiency (PCE) of 23.22% for an area of 0.12 cm2. Perovskite/silicon tandem cells with an area of 1 cm2 reached a PCE of 30.48%. Encapsulated tandem devices retained 95% of their initial PCE after 300 h of maximum power point tracking under 1‐sun illumination at 25 °C. [ABSTRACT FROM AUTHOR]

This paper delves into the indoor performance analysis of Perovskite/Silicon Tandem Solar Cells (PSSTC) through a detailed exploration utilizing numerically modeled energy band diagrams. The primary objective is to uncover the potential of PSSTC for solar energy conversion in indoor settings. Various tandem cell configurations are scrutinized under diverse artificial lighting spectra, with an innovative Li4Ti5O12/CsPbCl3/MAPbBr3/CH3NH3PbI3/Si architecture achieving an exceptional maximum power conversion efficiency of 25.25%. This represents a substantial efficiency enhancement of nearly 7% compared to standalone Silicon cells. The study underscores the significance of design optimization in maximizing performance. The energy band diagram analysis reveals a strong correlation with the I-V characteristics, providing valuable insights into solar cell performance under varied optical injections. Notably, the Xenon light source exhibits a higher deviation of the quasi-Fermi level, resulting in increased current density surpassing the AM1.5G conditions by approximately 2.5 mA/cm2. These findings underscore the promising potential of PSSTC for highly efficient indoor solar energy conversion and emphasize the critical role of design optimization in unlocking peak performance. [ABSTRACT FROM AUTHOR]

Tin‐lead (Sn‐Pb) mixed perovskite solar cells (PSCs), which serve as bottom subcells in all‐perovskite tandem solar cells, are pivotal for developing highly efficient solar cells. However, the vulnerability of stannous (Sn2+) to spontaneous oxidation to harmful tetravalent tin (Sn4+) presents significant challenges. Here, a “mouse glue trap” strategy is proposed to mitigate this issue by introducing a multifunctional additive, oxamidic acid potassium salt (OAPS). This approach effectively traps undesired Sn4+ impurities through strong interactions between the oxaminic acid groups of OAPS and Sn4+ impurities. Additionally, OAPS, with its unique functional groups, can inhibit Sn2+ oxidation, passivate defects, alleviate stress, and improve crystalline quality in Sn‐Pb mixed perovskite films. As a result, the enhanced Sn‐Pb mixed narrow‐bandgap PSCs incorporating OAPS achieve a power conversion efficiency of 22.04% and exhibit improved storage stability, with 91% retention after 3072 h of storage in an N2‐filled glovebox. Moreover, all‐perovskite tandem cells using OAPS‐incorporated Sn‐Pb narrow‐bandgap PSCs as subcells demonstrate efficiencies of 27.17% and 28.31% for two‐terminal and four‐terminal tandems, respectively, presenting a straightforward approach to optimizing performance in Sn‐Pb mixed PSCs and their tandems. [ABSTRACT FROM AUTHOR]

This study investigates the optical properties (light reflectance, absorptance, transmittance, and scattering) of black silicon (b‐Si) layers formed using reactive ion etching method. The corresponding spectra are determined across the visible, near‐infrared, and near‐ultraviolet wavelength ranges (250–1400 nm). It is demonstrated that b‐Si layers reduce the reflectance, and increase the absorptance and light scattering due to the disordered distribution of the nanoneedles. Increasing the etching duration strengthens this trend. It is shown that b‐Si layers etched for 10 min can be considered perfect light scatterers upon reflection at wavelengths less than 700 nm. Based on the obtained results, the possible profits of light scattering from the b‐Si interlayer for perovskite/Si tandem solar cells are analyzed. It is substantiated that the b‐Si interlayer can increase the useful absorptance not only within the bottom Si solar subcell but also in the top perovskite solar subcell. The prospects for future research directions and challenges are also provided. [ABSTRACT FROM AUTHOR]

A facile and eco‐friendly dimethyl sulfoxide‐mediated solution aging (DMSA) treatment is presented to control the crystallization dynamics of methylammonium (MA)‐free wide‐bandgap (WBG) perovskite films, enhancing film quality, and morphology for high‐performance tandem solar cells. The comprehensive structural, morphological, and characterization analyses reveal that the DMSA treatment significantly enhances composition and morphology homogeneity while suppressing halide segregation. Consequently, opaque, and semi‐transparent MA‐free WBG perovskite solar cells (PSCs) exhibit remarkable power conversion efficiencies (PCEs) of 18.28% and 17.61%, respectively. Notably, the unencapsulated DMSA‐treated devices maintain 95% of the initial PCE after 900 h of continuous operation at 55 °C ± 5 °C. Furthermore, stacking semi‐transparent DMSA‐treated PSCs as top cells in a 4T tandem configuration, along with silicon heterojunction (SHJ), lead–tin (Pb–Sn) alloyed PSCs, and organic photovoltaics (OPV) as bottom cells, yields impressive PCEs of 28.09%, 26.09%, and 25.28%, respectively, for the fabricated tandem cells. This innovative approach opens new avenues for enhancing the photo‐stability and photovoltaic performance of perovskite‐based tandem solar cells. [ABSTRACT FROM AUTHOR]

As a result of an ongoing global dedication, metal‐halide perovskite (PVSK) has proven to be a promising substitute among other developed materials for next‐generation photovoltaic cells due to significantly high efficiency, economical reasons, environmentally friendly processing, and bandgap alterations. In just 12 years, PVSK‐based single cells have achieved an efficiency of 26.1%, reaching single‐crystal silicon solar cells at 27.6% and silicon heterostructure solar cells at 26.8%. PVSK‐based tandem cells also have achieved remarkable attention as a viable candidate for future‐generation photovoltaic technology. Currently, a considerable number of reports are documented as evidence of the efforts to integrate the wide‐bandgap PVSK either with itself (narrow‐bandgap PVSK ([NBG‐PVSK]) or other traditional (NBG) cells, including silicon (Si), copper–indium–gallium–selenide, organic solar cells, cadmium telluride (CdTe), and dye‐sensitized. Thanks to the substantial growth made in the advances of PVSK‐based tandem cells both in the laboratories and in the commercialization sector, this review will systematically elucidate the emergence of PVSK‐based cells, their current status, and applications in tandem configurations. Furthermore, this survey will cover the analysis of different strategies and efforts to achieve cutting‐edge photovoltaic technology. Finally, the commercialization of different PVSK‐based tandem technologies and their prospects are analyzed. [ABSTRACT FROM AUTHOR]

Monolithic perovskite/organic tandem solar cells (TSCs) have emerged as promising thin film solar cells. It is recognized that interconnect junction plays a pivotal role in tandem devices. Consequently, wide bandgap Cs0.25FA0.75Pb(I0.6Br0.4)3 perovskite top-cell and narrow bandgap PM6:Y6:PC61BM ternary organic bottom-cell were integrated in this study with several kinds of thin metal interconnect layers, which provides feasibility to elaborately manipulate light transmission and carrier tunneling process in interconnect junction. It is confirmed that, in comparison with Au, employing an Ag interconnect layer elevates integrated transmittance of light in longer wavelength regions, mainly because of the alleviated screening effect with a lower free electron concentration, which offers sufficient light harvest for the bottom-cell. Meanwhile, established energy barriers with moderate height afford convenient extraction and recombination for both holes and electrons. Hence, the performance of TSCs is promoted substantially. Moreover, an innovative Ag/Au double interconnect layer is proposed accordingly, which can preserve exceptional conductivity and light transmission and further reduce barrier height, especially for hole tunneling, by optimizing the band alignment between the interconnect layer and bottom-cell. Resultantly, the monolithic perovskite/organic TSC with a striking efficiency of 23.26% is achieved. In a word, this study can pave a general approach toward high-performance TSCs integration. [ABSTRACT FROM AUTHOR]

Inverted perovskite solar cells (PSCs) are preferred for tandem applications due to their superior compatibility with diverse bottom solar cells. However, the solution processing and low formation energy of perovskites inevitably lead to numerous defects at both the bulk and interfaces. We report a facile and effective strategy for precisely modulating the perovskite by incorporating AlOx deposited by atomic layer deposition (ALD) on the top interface. We find that Al3+ can not only infiltrate the bulk phase and interact with halide ions to suppress ion migration and phase separation but also regulate the arrangement of energy levels and passivate defects on the perovskite surface and grain boundaries. Additionally, ALD‐AlOx exhibits an encapsulation effect through a dense interlayer. Consequently, the ALD‐AlOx treatment can significantly improve the power conversion efficiency (PCE) to 21.80 % for 1.66 electron volt (eV) PSCs. A monolithic perovskite‐silicon TSCs using AlOx‐modified perovskite achieved a PCE of 28.5 % with excellent photothermal stability. More importantly, the resulting 1.55 eV PSC and module achieved a PCE of 25.08 % (0.04 cm2) and 21.01 % (aperture area of 15.5 cm2), respectively. Our study provides an effective way to efficient and stable wide‐band gap perovskite for perovskite‐silicon TSCs and paves the way for large‐area inverted PSCs. [ABSTRACT FROM AUTHOR]

Tandem solar cells present an efficient way to boost solar energy conversion, potentially advancing performance and widespread photovoltaic technology adoption. This study employed a novel approach to grow Sb2S3 thin films onto a c-Si (100) substrate using a sol-gel dip-coating technique. The as-deposited samples exhibited an amorphous nature, indicating the necessity for a thermal annealing step. The impact of annealing temperature on the phase purity, structure, morphological, optical, and photovoltaic properties of the synthesized hetero-structure Sb2S3/c-Si (100) was examined using secondary ion mass spectrometry (SIMS), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), and UV-visible spectroscopy. SIMS analysis revealed uniformity and consistent composition in the deposited films with a thickness of approximately 700 nm on the silicon substrate. XRD measurements revealed a polycrystalline structure in all films after annealing in an argon atmosphere, except for the as-deposited one. The Sb2S3 film annealed at 320 °C exhibited the highest crystallite size of about 53 nm. The optical parameters such as refractive index n(λ) and extinction coefficient k(λ) were estimated using the Fresnel matrix method. The Sb2S3/c-Si heterojunction exhibited obvious rectification characteristics according to the current vs. voltage (I-V) curve under dark conditions. The illuminated current density-voltage characteristic of the best hetero-junction Ag/ Sb2S3/c-Si (100)/Al annealed at 320 °C exhibits a short-circuit current density (Jsc) of 13.16 mA cm− 2, an open circuit voltage (Voc) of 730 mV, and fill factor (FF) of 0.62 yielding power conversion efficiencies (PCE) of 6.15%.under AM 1.5 sun. [ABSTRACT FROM AUTHOR]

The development of efficient all perovskite tandem solar cells has faced challenges related to current matching and optical losses. In this work, a design of a non‐coplanar three‐terminal (3T) all perovskite tandem solar cell is presented, which consists of a p‐i‐n inverted NiOX‐based CsPbI2Br perovskite top cell, and a FA0.6MA0.4Sn0.5Pb0.5I3 perovskite bottom cell with back‐contact (BC) device structure. It effectively mitigated the optical losses introduced in non‐absorbing layers and resulted in a 2.9% absolute efficiency improvement compared to that of planar sandwich‐type 3T tandems. Both optical and electrical characteristics of the multi‐terminal tandem cells are investigated. Then, it is focused on understanding the impact of top cell thickness on overall non‐coplanar BC 3T‐tandem performance, considering low‐energy photon optical reflection and carrier transport distance. Following optimizations of energy level and device structure, an efficiency of 32.16% is achieved, with non‐coplanar BC 3T device architecture: top cell consisting of hole extraction layer (ITO/NiOx), CsPbI2Br absorber layer, and electron extraction layer (ZnO/FA0.6MA0.4Sn0.5Pb0.5I3/SnO2/Ag); and bottom cell (Ni/NiOx/FA0.6MA0.4Sn0.5Pb0.5I3/SnO2/Ag); bottom perovskite layer has two functions, one is electron transport layer for top cell, and the other is low‐energy photon absorption layer in bottom cell. It provides insight and a promising pathway for manufacturing high‐efficient all perovskite tandem solar cells. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells with synthesized phenothiazine derivative 3,7′-bis(2-cyano-1-acrylic acid)-10-ethyl-phenothiazine (PTZ) and commercial di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) (N719) dyes were fabricated and characterized based on current–voltage measurements. The effect of the utilization of individual dyes and its mixture, chenodeoxycholic acid as co-adsorbent addition, replacement of I−/I3− by Co2+/3+ ions in electrolyte and platinum by semiconducting polymer mixture poly(3,4-ethylenedioxythiophene) polystyrene sulfonate in counter electrode was studied. Additionally, the effect of polymer thickness on the photovoltaic performance of the device was evaluated. Prepared photoanodes were characterized by UV–Vis spectroscopy and atomic force microscopy. The further modification of DSSCs involving the fabrication of tandem solar cells was carried out. The higher power conversion efficiency 7.60% exhibited tandem photovoltaic cell sensitized with dyes mixture containing co-adsorbent, I−/I3− ions in the electrolyte, and platinum in the electrode. [ABSTRACT FROM AUTHOR]

Perovskite‐based tandem solar cells have demonstrated high potential for overcoming the Shockley–Queisser limit. Routine bandgap (RBG, ≈1.55 eV) perovskites have achieved a perfect balance between efficiency and stability. The narrow bandgap (NBG) candidates for RBG perovskite‐based tandem devices are very limited. Lead sulfide (PbS) colloidal quantum dots (CQDs) are a promising partner due to their broad absorption spectra. However, the efficiency of RBG perovskite/QD tandem devices still lags behind. Herein, efficient RBG perovskite/QDs four‐terminal tandem photovoltaics are successfully implemented through synergistic enhancement from transparent electrode and band alignment Engineering. For tin doped indium oxide (ITO) electrodes, their conductivity and near‐infrared transparency are leveraged using magnetron sputtering and reactive plasma deposition (RPD) methods. Furthermore, instead of traditional zinc oxide, aluminum‐doped zinc oxide (AZO) is developed to enhance the carrier extraction capability of PbS QD bottom cells. Based on the above enhancements, ≈0.95 eV PbS solar cells achieve a record efficiency of 14.14%. Integrated with the front semi‐transparent perovskite solar cells, the four‐terminal perovskite/QD tandem device reaches a record efficiency of 26.12%. The synergistic combination of the RBG perovskite and NBG QD devices provides promising prospects for tandem photovoltaics. [ABSTRACT FROM AUTHOR]

The tandem solar cell presents a potential solution to surpass the Shockley–Queisser limit observed in single-junction solar cells. However, creating a tandem device that is both cost-effective and highly efficient poses a significant challenge. In this study, we present proof of concept for a four-terminal (4T) tandem solar cell utilizing a wide bandgap (1.6–1.8 eV) perovskite top cell and a narrow bandgap (1.2 eV) antimony selenide (Sb2Se3) bottom cell. Using a one-dimensional (1D) solar cell capacitance simulator (SCAPS), our calculations indicate the feasibility of this architecture, projecting a simulated device performance of 23% for the perovskite/Sb2Se3 4T tandem device. To validate this, we fabricated two wide bandgap semitransparent perovskite cells with bandgaps of 1.6 eV and 1.77 eV, respectively. These were then mechanically stacked with a narrow bandgap antimony selenide (1.2 eV) to create a tandem structure, resulting in experimental efficiencies exceeding 15%. The obtained results demonstrate promising device performance, showcasing the potential of combining perovskite top cells with the emerging, earth-abundant antimony selenide thin film solar technology to enhance overall device efficiency. [ABSTRACT FROM AUTHOR]

Developing tandem solar cells is an excellent strategy to break through the Shockley–Queisser (SQ) limit for single-junction solar cells. A major factor in developing a tandem solar cell is to make it cost-efficient with high device performance. Here, we demonstrate the proof of concept of four terminal (4T) tandem solar cell using a perovskite solar cell (PSC) as a wide bandgap (WBG) top cell and narrow bandgap (NBG) cadmium telluride (CdTe) as a bottom cell. A 4T tandem device power conversion efficiency (PCE) exceeding 23% was obtained using SCAPS (solar cell capacitance simulator) simulation, demonstrating the architecture’s feasibility. Further, we fabricated two WBG semitransparent perovskite cells with different bandgaps (1.6eV and 1.77eV) and mechanically stacked it with NBG CdTe (1.5eV) to obtain tandem efficiencies of 18.2% and 19.4% respectively. From the results, we concluded that the PSC with a bandgap of 1.77eV is more suitable to be paired with the NBG CdTe solar cell to get good device performance and effective spectral utilization. The experimental results show promising device performance and pave the way to further improve device performance by engineering the device architecture and interfaces.

The tandem solar cell presents a potential solution to surpass the Shockley–Queisser limit observed in single-junction solar cells. However, creating a tandem device that is both cost-effective and highly efficient poses a significant challenge. In this study, we present proof of concept for a four-terminal (4T) tandem solar cell utilizing a wide bandgap (1.6–1.8 eV) perovskite top cell and a narrow bandgap (1.2 eV) antimony selenide (Sb2Se3) bottom cell. Using a one-dimensional (1D) solar cell capacitance simulator (SCAPS), our calculations indicate the feasibility of this architecture, projecting a simulated device performance of 23% for the perovskite/Sb2Se3 4T tandem device. To validate this, we fabricated two wide bandgap semitransparent perovskite cells with bandgaps of 1.6 eV and 1.77 eV, respectively. These were then mechanically stacked with a narrow bandgap antimony selenide (1.2 eV) to create a tandem structure, resulting in experimental efficiencies exceeding 15%. The obtained results demonstrate promising device performance, showcasing the potential of combining perovskite top cells with the emerging, earth-abundant antimony selenide thin film solar technology to enhance overall device efficiency.

The majority of numerical research on kesterite tandem solar cells has predominantly focused on a two‐terminal (2T) configuration that utilizes an ideal tunnel junction. Herein, the performance of kesterite tandem solar cells by introducing a photonic crystal structure (1DPC) as intermediate layer in both three‐terminal (3T) and four‐terminal (4T) configurations is investigated. The photonic crystal (1DPC) is designed by stacking ITO and SiO2 layers with the terminal layer consisting of NiO. Optical properties of the 1DPC are modeled. This innovative approach offers several advantages. 1) The 1DPC selectively reflects lower wavelengths, effectively enhancing the short‐circuit current density (Jsc) of the top subcell, while the solar irradiance spectrum at higher‐wavelength optimum for the subcell is not affected. 2) The 1DPC serves as an intermediate electrode, needed for the 3T or 4T configuration. 3) Replacing the conventional Mo back contact with a NiO layer significantly boosts the open‐circuit voltage (Voc) of the top subcell. The findings demonstrate that these configurations exhibit higher performance compared to previously reported results. Furthermore, the utilization of 3T and 4T configurations, incorporating the 1DPC as an electrical beam splitter, provides an effective and accurate design compared to the 2T configuration using ideal tunnel junctions. [ABSTRACT FROM AUTHOR]

The realization of efficient large-area perovskite solar cells stands as a pivotal milestone for propelling their future commercial viability. However, the upscaling fabrication of perovskite solar cells is hampered by efficiency losses, and the underlying growth mechanism remains enigmatic. Here, it is unveiled that a prevalent upscaling technology, namely blade-coating, inherently triggers top-down inhomogeneity strains, predominantly concentrated on the surface of wide-bandgap perovskite films. Through strain mitigation strategies, the perovskite films exhibit reduced halide vacancies, leading to enhanced stability and improved optoelectronic characteristics. Consequently, the blade-coated perovskite solar cells achieve minimal efficiency loss when transitioning from small-area to large-area devices, enabling the realization of 1 cm²-area 1.77 eV-bandgap cells with a remarkable efficiency of 18.71%. Additionally, the strain-relieved device exhibits an exceptional 109% retention of its initial efficiency even after 400 h of continuous operation, in stark contrast to the control device which experiences a decline to 91%. Furthermore, the resulting 4-terminal all-perovskite tandem solar cells crafted utilizing blade-coated 1.77 eV-bandgap subcells achieve a maximum efficiency of 27.64% (stabilized at 27.28%). This study not only sheds light on the intricacies of upscaling preparation techniques but also overcomes potential obstacles that can impede the trajectory toward achieving large-scale perovskite solar cells. [ABSTRACT FROM AUTHOR]

Perovskite/silicon tandem solar cells are of great interest due to their potential for breaking the Shockley-Queisser limit of single-junction silicon solar cells. Perovskite solar cells are widely used as the top subcells in perovskite/silicon tandem solar cells due to their high efficiency and lower fabrication cost. Herein, we review the semi-transparent perovskite solar cell in terms of the mechanisms of their translucent structure, transparent electrodes, charge transport layer, and component modification. In addition, recent progress in the research and development of 4T perovskite/silicon tandem solar cells is summarized, with emphasis on the influence of perovskite structure and silicon cells on the progress of tandem solar cells. Finally, we discuss the challenges associated with 4T perovskite/silicon tandem solar cells and suggest directions for the development of perovskite/silicon commercialization. [ABSTRACT FROM AUTHOR]

Machine learning (ML) is gaining more attention in photovoltaic research and will be a vital tool in reaching record‐high power conversion efficiencies (PCE) in the near future. One area, where ML is significantly beneficial is reducing the number of experiments needed to find the optimum combination of parameters in solar cell fabrication. Bayesian optimization (BO) provides routes for quickly identifying optimum parameters in problems with large parameter space. In this work, BO algorithms utilizing previous knowledge are demonstrated to result in faster optimization of tandem solar cells, a technology rapidly gaining more interest due to its potential to deliver record‐high performance. Namely, it is shown that in the space of all possible parameter combinations that take ≈88 years to evaluate, optimum PCE can be obtained in 20 min. Moreover, it is demonstrated that methods utilizing previous knowledge outperform those that do not by yielding an increase of ≈8.9%abs. in the 1st iteration and requiring 5× less time to reach a target PCE of 38.5% across 20 different trials. Results from this work help accelerate the development of tandem solar cells by removing the need for large numbers of experiments in identifying optimum parameters. [ABSTRACT FROM AUTHOR]

Tandem solar cells (TSCs) based on metal halide perovskites offer a route to increase power conversion efficiency (PCE). However, there are limited options for narrow‐bandgap bottom subcells. Colloidal quantum dots‐based solar cells are found attractive for this role. Herein, a cost‐effective two‐terminal (2T) monolithic TSC structure consisting of wide‐bandgap all‐inorganic perovskite CsPbI3$\left(\text{CsPbI}\right)_{3}$ top subcell and narrow‐bandgap chalcogenide PbS quantum dots bottom subcell is proposed. For optimization of the PCE of the tandem structure, standalone and tandem analysis are done in terms of variation of absorber layer thickness, total defect density, interfacial defect density, back metal contact, current density voltage (J–V) curves, external quantum efficiency, current matching, and tandem photovoltaic parameters. Optimized TSCs designed with the 530 nm/450 nm‐thick absorber layers of top/bottom sub cells result in JSC$J_{\text{SC}}$ of 19.28 mA cm−2, VOC$V_{\text{OC}}$ of 1.89 V, and PCE of 27.32%. It is found that performance of the device is very sensitive to the total defect density of the bottom subcell. Therefore, high PCE can be obtained by controlling the total defect density of the bottom subcell. This work motivates the experimental realization of low‐cost, high‐efficiency TSCs for further research. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Research on Many-Body Systems is the property of Shahid Chamran University of Ahvaz and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Research on Many-Body Systems is the property of Shahid Chamran University of Ahvaz and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thermal evaporation can significantly facilitate scalable, uniform, and conformal perovskite film, particularly well‐suited for the preparation of perovskite/silicon (Si) tandem solar cells. However, the perovskite material easily induces a phase transition from a photoactive phase to a photoinactive phase, limiting the development of the stability and efficiency of tandem cells. Introducing lead chloride (PbCl2) into wide‐bandgap perovskite materials is beneficial for the fabrication of efficient and stable light‐absorbing materials, but the microscopic mechanism of the effect of PbCl2 on perovskite is still unclear. The study here reports evidences that the addition of PbCl2 to improve perovskite film stability and optoelectronic performance is due to the minor octahedral tilting of the perovskite structure are reported. It also demonstrates that this strategy accelerates interfacial charge transfer and carrier diffusion in the perovskite bulk and heterojunction interfaces. Therefore, the wide‐bandgap perovskite solar cells (PSCs) prepared by adding PbCl2 exhibit a champion power conversion efficiency (PCE) of 17.80%. The PSCs retain 97% of their performance following 200 h of operation at the maximum power point under full 1‐sun illumination. Finally, monolithic perovskite/Si tandem cells with record PCEs of 27.43% and an open‐circuit voltage of 1.817 V are fabricated. [ABSTRACT FROM AUTHOR]

Three‐terminal tandem solar cells (3 T TSCs) have recently sparked increasing interest as they feature a lean monolithic device architecture similar to two‐terminal TSCs and, like four‐terminal TSCs, do not require current matching for optimal operation. In this contribution, detailed balance limit calculations for different combinations of top and bottom cell bandgaps are conducted to determine the optimum bandgap pairing and limiting efficiency of 3T TSCs. An experimental realization of a 3T TSC with perovskite and silicon sub‐cells and a combined efficiency of 28.9% is presented and used to derive a realistic parameterization for non‐radiative recombination. Herein, the optimum bandgap pairing and resulting maximum efficiency under voltage‐matched conditions for voltage‐matching ratios of 1:2 and 2:3, which is relevant for stringing and module integration of 3T TSCs, are further determined. To this end, non‐radiative recombination is incorporated in the model and quantified by matching theoretical open‐circuit voltages and those of real‐world high‐efficiency solar cells based on different absorber materials (and thus bandgaps), including the perovskite top cell of the best in‐house 3T TSC. [ABSTRACT FROM AUTHOR]

Abstract Perovskite‐organic tandem solar cells (TSCs) have emerged as a groundbreaking technology in the realm of photovoltaics, showcasing remarkable enhancements in efficiency and significant potential for practical applications. Perovskite‐organic TSCs also exhibit facile fabrication surpassing that of all‐perovskite or all‐organic TSCs, attributing to the advantageous utilization of orthogonal solvents enabling sequential solution process for each subcell. The perovskite‐organic TSCs capitalize on the complementary light absorption characteristics of perovskite and organic materials. There is a promising prospect of achieving further enhanced power conversion efficiencies by covering a broad range of the solar spectrum with optimized perovskite absorber, organic semiconductors as well as the interconnecting layer's optical and electrical properties. This review comprehensively analyzes the recent advancements in perovskite‐organic TSCs, highlighting the synergistic effects of combining perovskite with a low open‐circuit voltage deficit, organic materials with broader light absorption, and interconnecting layers with reduced optical and electrical loss. Meanwhile, the underlying device architecture design, regulation strategies, and key challenges facing the high performance of the perovskite‐organic TSCs are also discussed.

In widely studied organic–inorganic hybrid perovskites, the organic component tends to volatilize and decompose under high temperatures, oxygen, and humidity, which adversely affects the performance and longevity of the associated solar cells. In contrast, all-inorganic perovskites demonstrate superior stability under these conditions and offer photoelectric properties comparable to those of their hybrid counterparts. The potential of tandem solar cells (TSCs) made from all-inorganic perovskites is especially promising. This review is the first to address recent advancements in TSCs that use all-inorganic perovskites and crystalline silicon (c-Si), both domestically and internationally. This work provides a systematic and thorough analysis of the current challenges faced by these systems and proposes rational solutions. Additionally, we elucidate the regulatory mechanisms of all-inorganic perovskites and their TSCs when combined with c-Si, summarizing the corresponding patterns. Finally, we outline future research directions for all-inorganic perovskites and their TSCs with c-Si. This work offers valuable insights and references for the continued advancement of perovskite-based TSCs.

Tandem solar cells are rationally designed and fabricated by stacking multiple subcells to achieve power conversion efficiency well above the Shockley‐Queisser (SQ) limit. There is a large selection pool for the subcell candidates, such as Si, III–V, Kesterite, Perovskite, and organic solar cells. A series of different combinations of these subcells have been successfully demonstrated in practical tandem solar cell devices. However, there has not been a systematic summary of how to connect subcells in a tandem solar cell using a practical, cost‐effective, and efficiency‐beneficial fashion. In this work, the connection manners of subcells within a tandem cell are classified into three main categories, performing sequential growth, using the physical connection, and applying an intermediate layer, focusing on systematical description of intermediate layers using different materials. The advantages and disadvantages of these connection methods and their applicability to tandem cell types are further elaborated using two typical example models, III–V/Si and Perovskite inclusive tandem cell devices. Eventually, this work can provide useful guidance on how to carry out a suitable intermediate connection in the design of tandem solar cells depending on the selected subcells and device structure. [ABSTRACT FROM AUTHOR]

A tandem solar cell, which is composed of a wide bandgap (WBG) top sub‐cell and a narrow bandgap (NBG) bottom subcell, harnesses maximum photons in the wide spectral range, resulting in higher efficiency than single‐junction solar cells. WBG (>1.6 eV) perovskites are currently being studied a lot based on lead mixed‐halide perovskites, and the power conversion efficiency of lead mixed‐halide WBG perovskite solar cells (PSCs) reaches 21.1%. Despite the excellent device performance of lead WBG PSCs, their commercialization is hampered by their Pb toxicity and low stability. Hence, lead‐free, less toxic WBG perovskite absorbers are needed for constructing lead‐free perovskite tandem solar cells. In this review, various strategies for achieving high‐efficiency WBG lead‐free PSCs are discussed, drawing inspiration from prior research on WBG lead‐based PSCs. The existing issues of WBG perovskites such as VOC loss are discussed, and toxicity issues associated with lead‐based perovskites are also addressed. Subsequently, the natures of lead‐free WBG perovskites are reviewed, and recently emerged strategies to enhance device performance are proposed. Finally, their applications in lead‐free all perovskite tandem solar cells are introduced. This review presents helpful guidelines for eco‐friendly and high‐efficiency lead‐free all perovskite tandem solar cells. [ABSTRACT FROM AUTHOR]

In this work, the effect of a varying spectral irradiance and top cell bandgap on the energy harvesting efficiency of two‐terminal (2T) and four‐terminal (4T) perovskite//silicon tandem solar cells under outdoor operating conditions is investigated. For the comparison, an optoelectronic model employing a 1 year outdoor data set for a 4T mechanical stacked gallium arsenide (GaAs) on crystalline silicon (Si) tandem device is first validated. Then, the verified model is used to simulate perovskite//silicon tandem devices with a varying perovskite top cell bandgap for a location in Golden, Colorado, USA. A spectral binning method to efficiently reduce and improve the visualization of the 1 min‐resolved environmental data while maintaining the simulation accuracy is introduced. The findings reveal that, for a device that is current matched under standard testing conditions, the annual spectral deviation reduces the energy harvesting efficiency by only 2%rel. When additional realistic losses for the 4T are taken into account, 2T devices are shown to have an energy‐harvesting efficiency that is at parity or higher. Deviations in the top cell bandgap are more than 0.1 eV from current matching result in a reduced energy harvesting efficiency of more than 5%rel for the 2T tandem device. [ABSTRACT FROM AUTHOR]

Multi‐absorbers, and tandem solar cells (TSCs), have enticed research focus with their competitive advantage of crossing the limits posed by Shockley–Queisser efficiency by single‐junction solar cell (SC). Perovskite solar cells (PSC) with their bandgap tunability and ease of solution processing at low temperatures for securing high efficiency (25.8%) provide an ideal candidate for top cell in TSC. Simultaneously, Si SCs with a 95% market share and their ideal low bandgap (1.12 eV) for capturing high‐energy photons in the near‐infrared (NIR) can assume bottom cell in TSC. This review highlights the research perspective for perovskite/Si TSCs to expedite its emergence as future TSC. The 4T device architecture of perovskite/Si TSC optically couples the subcells whereas the 2T configuration ensures the optical and electrical coupling among the constituent subcells. The semitransparency of the top cell, flat as well as textured Si bottom cell, matching of the current between the subcell through the recombination and tunnel junction layers, and modification of perovskites through‐thickness variation are few worth‐considering factors that contribute toward highly efficient perovskite/Si TSC. Finally, the research insight about perovskite/Si and all‐perovskite TSC is analyzed with reference to the ideal choice for the bottom cell. [ABSTRACT FROM AUTHOR]