Efficient perovskite photovoltaic devices using chemically doped PCDTBT as a hole-transport material

Abstract

It is shown that by chemically doping the carbazole-based conjugated polymer PCDTBT using the molecular materials TBP, LiTFSI and FK209, its conductivity can be increased by a factor of 10⁵ times. Such doped PCDTBT films are used as a hole transport material (HTM) for standard architecture (CH(NH₂)₂PbI₃)_0.85(CH₃NH₃PbBr₃)_0.15 perovskite solar cells (PSCs). We show that devices with optimised PCDTBT thickness and doping level achieve a peak power conversion efficiency (PCE) of 15.9%. We expect a number of related doped conjugated polymers to also be capable of acting as efficient HTMs for PSCs.