Boosting the efficiency and stability of CsPbBr₃ perovskite solar cells through modified multi-step spin-coating method

In this research, we enhance the stability of all-inorganic CsPbBr3 perovskite solar cells using a modified multi-step spin-coating technique. By introducing low-concentration CsBr and PbBr2 in two additional steps, we achieve a PbBr2 layer with fewer pinholes, improved crystallinity, and a smoother surface. This promotes the formation of a high-quality CsPbBr3 film with larger grains by incorporating a derivative-phase CsPb2Br5. This film reduces interface defects, enhances grain growth, and boosts power conversion efficiency from 5.43% to 9.36%. Notably, unencapsulated devices maintain stable performance for over 2400 h in ambient air conditions.