Lead-free Cs2BiAgI6 has garnered a lot of research interest recently due to its suitability as a potential absorber layer in the solar cell (SC) architecture owing to its low cost, good stability, and high efficiency. The main highlight of this research work includes the photovoltaic (PV) performance enhancement of Cs2BiAgI6 double perovskite solar cells (PSCs) by optimizing the optoelectronic parameters of the absorber, electron transport layer (ETL), hole transport layer (HTL), and various interface layers. Solar Cell Capacitance Simulator One dimension (SCAPS-1D) numerical simulation was used to optimize the performance of Cs2BiAgI6 absorber-based SCs consisting of copper barium thiostannate (CBTS) as the HTL and TiO2, PCBM, ZnO, IGZO, SnO2, and WS2 as ETLs. The role of the non-lead cesium-based halide perovskite absorber layer in the improvement of the SC performance was systematically investigated through a variation in the thickness, doping density, and defect density of the absorber layer, ETL, and HTL. The performance of the investigated device architectures is largely dependent on the thickness of the absorber layer, acceptor density, defect density, and the combination of different ETLs and HTLs. We found that TiO2, PCBM, ZnO, IGZO, SnO2, and WS2 ETL-based optimized devices recorded a power conversion efficiency (PCE) of 23.14, 23.71, 23.69, 22.97, 23.61, and 21.72%, respectively. Furthermore, the effect of series and shunt resistances, temperature, capacitance, and Mott–Schottky for the six optimized devices was estimated along with the computation of the corresponding generation and recombination rates, current density–voltage (J–V), and quantum efficiency (QE) characteristics. The PV parameters obtained from this comprehensive analysis are finally compared with the earlier published theoretical and experimental reports on Cs2BiAgI6 absorber-based SCs.

In this study, we investigated the potential of CsPbI3 as an absorber material for use in perovskite solar cells (PSCs). To optimize the device, we used TiO2 as the electron...

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The power conversion efficiency (PCE) of cesium lead halide (CsPbX3, X = l, Br, and Cl)-based all-inorganic perovskite solar cells (PSCs) is still struggling to compete with conventional organic–inorganic halide perovskites. A combined material and device-related analysis is much needed to understand the working principle to explore the efficiency potential of CsPbX3-based PSCs. Therefore, here, density functional theory (DFT) and SCAPS-1D-based studies were reported to evaluate the photovoltaic (PV) performance of CsPbBr3-based PSCs. DFT is first applied to assess and extract structural and optoelectronic properties (band structure, density of states, Fermi surface, and absorption coefficient) of the considered absorber layer. The calculated electronic band gap (E g) of the CsPbBr3 absorber was 1.793 eV, which matched well with the earlier computed theoretical value. Additionally, the Pb 6p orbital contributed largely to the calculated density of states (DOS), and the electronic charge density map showed that the Pb atom acquired the majority of charges. In order to examine the optical response of CsPbBr3, optical characteristics were computed and correlated with electronic properties for its probable photovoltaic applications. Fermi surface computation showed multiband characters. Furthermore, to look for a suitable combination of the charge transport layer, a total of nine HTLs (Cu2O, CuSCN, P3HT, PEDOT:PSS, Spiro-MeOTAD, CuI, V2O5, CBTS, and CFTS) and six ETLs (TiO2, PCBM, ZnO, C60, IGZO, and WS2) are used considering the experimental E g (2.3 eV). The best power conversion efficiency (PCE) of 13.86% is reported for TiO2 and CFTS in combination with the CsPbBr3 absorber. The effects of operating temperature, series and shunt resistances, Mott–Schottky, capacitance, generation and recombination rates, quantum efficiency, and current–voltage density were also examined. The resulting PV properties were also compared with previously published data. Results reported in this study will pave the way for the development of high-efficiency all-inorganic CsPbBr3-based solar cells in the future.

Cs 3 Bi 2 I 9 as a solar absorber material is a strong contender for lead-free perovskite solar cells (PSCs). The presence of bismuth (Bi) in Cs 3 Bi 2 I 9 leads to the origin of interesting optoelectronic properties along with a suitable optical band gap and high absorption coefficient. However, further analysis of the crystal structure, optical, and electronic properties of this material is required for efficient photovoltaic (PV) applications. The potential of Cs 3 Bi 2 I 9 perovskite as an absorber layer for solar cells (SCs) was first analyzed by performing density functional theory (DFT) calculations to observe its structural, optical, and electronic properties. Band structure reveals an indirect band gap (2.42 eV), and density of states (DOS) data show good conductivity primarily contributed by the 5p and 6s orbital electrons of I and Bi atoms. Strong electronic charge buildup is seen in the electronic charge density map surrounding the I atom, as well as the covalent bonds between the I and Bi atoms. The frequency-dependent dielectric function and absorption calculations reveal that Cs 3 Bi 2 I 9 might be a potential material in optoelectronic and photovoltaic systems. We also performed numerical simulations using the one-dimensional solar cell capacitance simulator (SCAPS-1D) for 49 different PSC configurations with Cs 3 Bi 2 I 9 absorber, electron transport layers (ETLs) comprising WS 2 , indium−gallium−zinc oxide (IGZO), SnO 2 , ZnO, C 60 , TiO 2 , and phenyl-C61-butyric acid methyl ester (PCBM), and hole transport layers (HTLs) like Cu 2 O, CuSCN, NiO, poly(3-hexylthiophene) (P3HT), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), Spiro-MeOTAD, and CuI. Simulation results reveal that the Cu 2 O HTL exhibited the best power conversion efficiency (PCE) for all of the ETLs. Of the 49 configurations, the six best configurations with the Cu 2 O HTL and different ETLs were analyzed to study the effect of absorber and ETL thickness, series and shunt resistances, operating temperature, capacitance, Mott−Schottky, generation, and recombination rate on the PV performance. Current−voltage (J−V) characteristics and quantum efficiency (QE) were computed for all of these configurations to understand the impact of the absorber, ETL, and HTL on the PV parameters. This comprehensive simulation study will assist researchers in the fabrication of cheap and efficient PSCs without lead and open new horizons in the field of solar technology.