CuSCN as hole transport material with 3D/2D perovskite solar cells

We report stable perovskite solar cells having 3D/2D perovskite absorber layers and CuSCN as an inorganic hole transporting material (HTM). Phenylethylammonium (PEA) and 4-fluoro-phenylethylammonium (FPEA) have been chosen as 2D cations, creating thin layers of [PEA2PbI4] or [FPEA2PbI4] on top of the 3D perovskite. The 2D perovskite as an interfacial layer, neutralizes defects at the surface of the 3D perovskite absorber and can protect from moisture-induced degradations. We demonstrate excellent charge extraction through the modified interfaces into the inorganic CuSCN HTM, with device efficiencies of above 18%, compared to 19.3% with conventional spiro-OMeTAD. Furthermore, we show significantly enhanced ambient stability.