Impact of Cr doping on the structural and optoelectronic properties of a CsPbIBr2 perovskite solar cell

Abstract

Metal halide perovskites, particularly the cesium lead iodide bromide (CsPbIBr₂) composition, have become more and more popular in solar applications because of their remarkable optoelectronic properties. Although recombination losses and stability problems still exist, CsPbIBr₂ is a potential option with a bandgap of about 2.0 eV. This work aims to investigate the doping of CsPbIBr₂ with chromium (Cr) to overcome these difficulties. According to the results of ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and current–voltage (J–V) analyses, the structural, optical, and electrical properties of perovskite films doped with Cr are improved. Quantum size effects may be responsible for the observed bandgap drop (2.20 to 2.03 eV) when the crystal size increases (43.6–62.5 nm). Electronic band structures change, which in turn affects the bandgap energy of the material, as the size of the crystal becomes larger and the confinement of electrons shrinks. The Cr–CsPbIBr₂ device produces 12.06% efficiency as compared to 9.64% for pure CsPbIBr₂, which is a ground-breaking step towards safer and more effective perovskite solar cells.