Enhancing the structural and optoelectronic properties of double ETL nickel-doped CsPbIBr2 perovskite solar cells

Abstract

The structural, optoelectronic, and photovoltaic properties of CsPbIBr₂ perovskite films were significantly enhanced by incorporating 4% Ni doping and utilizing a double electron transport layer (ETL) consisting of titanium dioxide (TiO₂) and nickel-doped tungsten trioxide (Ni-WO₃). X-ray diffraction (XRD) analysis of perovskite film revealed an increase in crystal size from 29.9 nm to 55.2 nm and a decrease in lattice constant from 6.024 Å to 6.012 Å upon Ni doping, indicating improved crystallinity. The energy bandgap of pure and Ni-CsPbIBr₂ decreased from 2.0 eV to 1.94 eV, respectively, enhancing light absorption efficiency. The refractive index of pure and Ni-CsPbIBr₂ increased from 2.625 to 2.645, respectively, enhancing light trapping and absorption. J–V measurements showed an efficiency increase from 12.26% to 12.96% with the introduction of a double ETL, demonstrating significant advancements in perovskite solar cell performance.