Inverted perovskite solar cells based on inorganic hole transport material of CuInS2 with high efficiency and stability

In this paper, CuInS 2 nanocrystals were prepared and used to fabricate inverted perovskite solar cells (PSCs) with the CuInS 2 nanocrystals as a hole transport material (HTM). The average power conversion efficiency (PCE) of the PSCs with CuInS 2 is 16.22%, which is close to the average PCE of the NiO-based devices (17.32%). The PCE of the champion PSC with CuInS 2 has been reached 17.34%, and that of the control PSC with NiO (18.33%). Moreover the inverted PSCs with CuInS 2 present an enhanced stability compared with the NiO-based control devices. The PCE of the inverted PSCs based on CuInS 2 maintains 70% of the original when they are placed in ambient atmosphere for 96 h, while the PCE of the control devices with NiO decreased to 60% of the beginning. These results indicate that CuInS 2 nanocrystal is an excellent HTM which could be applied to assemble the inverted PSCs.