Enhancing efficiency of CsPbI <sub>2</sub> Br perovskite solar cells through polyimide passivation and thermal annealing
Annotatsiya
Abstract All-inorganic CsPbI 2 Br perovskite solar cells have been extensively investigated due to their superior thermal and phase stability. In this study, CsPbI 2 Br perovskite active layers incorporating 0.5% tranexamic acid were employed, while a surface passivation strategy using polyimide (PI) at a concentration of 0.5 mg ml −1 was applied to all samples during the film deposition process. The fabrication was carried out under ambient conditions at room temperature, highlighting its potential for scalable industrial applications. The optimal performance was achieved for the active layers annealed at 120 °C. X-ray diffraction (XRD) analysis confirmed that this annealing temperature promotes a highly ordered perovskite crystal lattice and enhances the overall stability of the perovskite solar cells, whereas higher annealing temperatures may induce structural degradation. Among the PI-passivated samples, increasing the annealing temperature led to a significant improvement in power conversion efficiency (PCE), rising from 10.5% at 80 °C to 13.1% at 120 °C.