Double inorganic hole extraction layer of Cs:NiOx/CuInS2 for efficiency and stability enhancement of perovskite solar cells

Summary In this work, we construct a double inorganic hole extraction layer (HEL) of Cs:NiO x /CuInS 2 by inserting a thin film of Cs:NiO x between the perovskite (FAPbI 3 ) 1-x (MAPbBr 3 ) x and CuInS 2 layers and fabricate n-i-p type perovskite solar cells (PSCs) using Cs:NiO x /CuInS 2 as HEL. The efficiency of the PSCs with Cs:NiO x /CuInS 2 reaches 18.04% from 16.13% for the devices with single HEL of CuInS 2 , which is close to the highest efficiency (19.24%) of the devices with double inorganic HEL reported. In addition, the operational stability of the devices with Cs:NiO x /CuInS 2 is enhanced. The solar cells based on double HEL of Cs:NiO x /CuInS 2 maintains 95% of the original PCE after keeping 32 days in ambient air, while the devices based on single HEL of CuInS 2 keeps only 84% of the original PCE. In addition, the thermal stability of the PSCs with Cs:NiO x /CuInS 2 is also enhanced compared with the devices based on CuInS 2 . The results demonstrate that the application of double HEL of Cs:NiO x /CuInS 2 can enhance the performance and stability of PSCs simultaneously.