An inorganic hole-transport material of CuInSe2 for stable and efficient perovskite solar cells

In this work, we synthesized CuInSe2 quantum dots (CISe QDs) and applied them to perovskite solar cells (PSCs) as an inorganic hole-transporting material (HTM). A power conversion efficiency (PCE) of 12.8% was achieved for the PSCs using CISe QDs as the HTM, which is the highest value reported to date for devices with a Cu-based chalcopyrite semiconductor as HTM. More importantly, the stability of PSCs with CISe QDs was significantly improved compared with that of the devices using spiro-OMeTAD as the HTM. These results demonstrate that CISe QDs are a promising inorganic HTM for PSCs with long-term stability and low cost.