Optical, structural, and electrical performance of CsPbIBr2 perovskites with zirconium doping and bilayer ETLs

This work studies the optoelectronic, and structural characteristics of CsPbIBr2 perovskite solar cells (PSCs) improved by 4 % Zirconium (Zr) doping and a bilayer electron transport layers (ETLs) composed of TiO2 and Zrdoped WO3. X-ray diffraction (XRD) examination of pure and Zr-doped CsPbIBr2 films revealed increased crystal size (39.2-41.2 nm) and lowered lattice constant following Zr doping, suggesting better crystallinity. The calculated energy band gap of pristine and Zr-doped CsPbIBr2 film decreases (1.986-1.926 eV), which improves the light absorption efficiency, while the increase in the refractive index implies that light is slowed down more as it passes through the material, which increases light trapping and absorption within the material. The XRD of Zr-WO3 ETL indicated a monoclinic crystal structure and increased lattice constant, allowing charge carrier transmission. Raman spectroscopy confirms the structural integrity of Zr-WO3. UV-Vis absorption spectra suggest enhanced absorption in the visible region and higher bandgap compared to Zr-doped CsPbIBr2. J-V tests reveal an efficiency rise from 8.54 % to 10.20 % with the proposed of double ETLs, exhibiting substantial breakthroughs in PSCs performance.