Study and Optimization of a New Perovskite Solar Cell Structure Based on the Two Absorber Materials Cs2TiBr6 and MASnBr3 Using SCAPS 1D

The main objective of this study is to optimize the photovoltaic parameters of a new perovskite solar cell structure (PSC) suggested, using the simulator solar cell capacitance simulator-one dimension (SCAPS-1D) which aims to improve its performance by adjusting different key variables. This new suggested cell which consists of six materials represents the major innovation point of our research, it is distinguished by a double active layer, composed of the two-cesium titanium hexabromide (Cs2TiBr6) and methylammonium tin tribromide (MASnBr3) perovskites. Using the SCAPS 1D software, the simulation allows to determine the optimal values of the various parameters to maximize the efficiency of the PSC. First, the effect of the thickness and defect densities of both Cs2TiBr6 and MASnBr3 materials on the output parameters was studied as well as the defect density in the interfaces. Subsequently, the doping density in Cs2TiBr6 and MASnBr3 was also optimized. Finally, the impact of temperature, series resistance and shunt resistance were evidenced. The results indicate that precise adjustments of these parameters can lead to significant improvements in photovoltaic performance, such as open circuit voltage of 1.105 V, short-circuit current density of 33.90 mA cm−2, fill factor of 88.01% and power conversion efficiency (PCE) 32.96%. These performances were obtained for a thickness of 700 nm for Cs2TiBr6 and 900 nm for MASnBr3, a defect density of 1014 cm−3 for each absorber layer, a defect density of 1014 cm−2 for each interface and a doping density of the order of 1018 cm−3 for each absorbent layer.