Optimizing the NiO x /Au Interface via Postannealing of the All-Inorganic CsPbIBr2 Perovskite Solar Cells for High Efficiency

All-inorganic perovskite solar cells (PSCs) have been demonstrated to solve the thermal instability problem of organic-inorganic hybrid PSCs. Therefore, NiO x film is prepared by electron beam evaporation as a hole transport layer of all inorganic CsPbIBr2 PSCs. Then, the postannealing is used to promote the diffusion of NiO x into the gold electrode, and enhance interface contact and reducing the electrical resistance of NiO x /Au. After optimizing NiO x /Au interface, the devices based on NiO x achieved a power conversion efficiency (PCE) of 6.7%. Furthermore, the best all-inorganic CsPbIBr2 PSC free of encapsulation retains 95% of initial efficiency over 100 h at 85 degrees C. Herein, an effective postannealing strategy is provided for optimized NiO x /Au interface to make stable and efficient all-inorganic CsPbIBr2 PSCs.

Automated summary

In this study, a postannealing strategy was utilized to optimize the NiOx/Au interface in order to improve the efficiency and stability of all-inorganic CsPbIBr2 perovskite solar cells. Through electron beam evaporation and postannealing, the efficiency of the devices based on NiOx reached 6.7%, with the best performing device retaining 95% of its initial efficiency over 100 hours at 85 degrees Celsius.