High performance Rb2AgBiI6 perovskite solar cell with optimized charge transport layers for space applications

Perovskite solar cells (PSCs), both lead-based and lead-free, offer a promising energy solutions for space applications owing to their lightweight design and excellent radiation resistance. In this work, we have introduced Rb₂AgBiI₆ lead-free double perovskite material as absorber layer due to its significant properties such as favorable band gap, superior thermal stability, less toxic nature and studied the performance of Rb₂AgBiI₆ based PSCs under high radiation exposure. Here, WS₂ and Cu₂O have been used as an ETL and HTL material, respectively, due to their suitable band alignment and high carrier mobility. The absorber layer parameters such as thickness, doping, defect density, interfacial effects, and electron affinity, were optimized to enhance the device performance. Additionally, device reliability has been improved by optimizing shunt resistances, temperature stability, and incident light intensity. The proposed device has attained power conversion efficiency of 29.32 % with open circuit voltage (V_OC) of 1.22 V, short-circuit current density (J_SC) of 27.62 mA/cm², and fill factor (FF) of 86.93 %. Furthermore, the impact of proton irradiation on proposed PSC was investigated, with a focus on ionization energy, recoil energy losses and vacancy production rates under different proton energies using SRIM simulator. Moreover, the proposed PSC demonstrates low ionization energy, reduced vacancy production rate and minimal recoil energy loss, highlighting its potential suitability for space applications. Additionally, the J–V characteristics of proposed PSC were analysed under AM0 and AM1.5G lighting conditions, both before and after proton irradiation, showcasing its robustness and efficiency in space-relevant environments.