Photovoltaic performance of CsPbBr3-based perovskite solar cell with TiO2 and quaternary chalcogenide Cu2FeSnS4 as charge transport channels: Unlocking >26% efficiency via SCAPS-1D investigation

Cesium-based perovskite solar cells (PSCs) have received tremendous research interest in the domain of photovoltaic due their high stability and low cost, but their performances are challenged with low output when compared to their organic-inorganic halide counterpart. In this research work, the one-dimensional solar cell capacitance simulation (SCAPS-1D) tool was used to investigate the photovoltaic (PV) performance of cesium lead bromide (CsPbBr₃)-based PSC with different hole transport layers (HTLs), which include copper(I) thiocyanate (CuSCN), copper(I) iodide (CuI), magnesium-doped copper chromium oxide (Mg-CuCrO₂), copper (II) oxide (CuO), copper antimony sulfide (CuSbS₂), copper iron tin sulfide (CFTS), and copper barium tin sulfide (CBTS). The best device configuration was ITO/TiO₂/CsPbBr₃/CFTS/Au, which gave a power conversion efficiency (PCE) of 12.665%, fill factor (FF) of 80.435%, current density (J_sc) of 17.595 mA/cm², and photo voltage (V_oc) of 0.895 V. Further study was carried out on the optimized configuration by varying the thickness of electron transport layer (ETL), doping concentration of ETL and absorber, defect density of the absorber, thickness of absorber, and thickness of HTL to obtain 0.01 μm, 10²⁰ cm⁻³, 10¹² cm⁻³, 10¹⁴ cm⁻², 0.5 μm, and 1.2 μm as optimized values. After proper simulation with the optimized data, a PCE of 26.032%, FF of 81.006%, J_sc of 34.908 mA/cm², V_oc of 0.921 V were obtained with TiO₂ and CFTS as charge transport channels. This shows an enhancement of ∼2.06 times in PCE, ∼1.01 times in FF, ∼1.98 times in J_sc, and ∼1.03 times in V_oc over the unoptimized device. Additionally, the influence of temperature, metal work function, series resistance, and shunt resistance was also studied, and it was found that the rise in temperature causes a shift in the concentration of carriers, giving rise to high rate of recombination which also results in influence on the saturation current, while an increase in series resistance results in a decrease in the device performance, which is attributed to discoloration. Low shunt resistance, results in losses in device output by giving an alternative pathway that limits the flow of current. This simulation alongside the validated results shows the real potential of CsPbBr₃ absorber, creating a major research pathway for the PV industry to develop less expensive and high-performing devices.