Designing and performance evaluation of solar cells with RbGeI 3 and RbGeBr 3 perovskites as double absorber layers: a numerical approach by SCAPS-1D

作者：Amir Bahrami, Neda Hasanzadeh · 发表于：Physica Scripta · 年份：2026 · DOI：10.1088/1402-4896/aea037 · 研究领域：Perovskite Materials and Applications、2D Materials and Applications、Thin-Film Transistor Technologies

Abstract This study presents a numerical investigation of a lead-free, all-inorganic halide perovskite solar cell featuring a double absorber layer architecture. The proposed device uses a hole transport layer (HTL)-free configuration with the structure FTO/ZnS/RbGeI3/RbGeBr3/Au, employing RbGeI3 and RbGeBr3 as the top and bottom absorber layers, respectively. The physical parameters of the proposed structure, including thickness, doping density, and defect density in the absorber layers, have been optimized and evaluated using SCAPS-1D software. In addition, an analysis of the internal electric field variation, energy band diagrams, and recombination rate has been carried out. The simulation results show that using the RbGeI3/RbGeBr3 perovskite heterojunction as a double absorber layer increases the external quantum efficiency (EQE) of the proposed model, particularly in the wavelength range of 750–950 nm. Due to the increase in photogenerated carriers and the formation of an internal electric field at the RbGeI3/RbGeBr3 interface, the transport of charge carriers is facilitated, thereby improving the overall device performance. Ultimately, for the proposed optimized structure, an efficiency of 29.22% is achieved, with an FF of 84.51%, a Jsc of 34.26 mA/cm2, and a Voc of 1.01 V. These values are significantly higher compared to the efficiencies of 21.54% for the single layer RbGeI3 and 18.80% for the single layer RbGeBr3. The findings of this study indicate that the use of R...