Hybrid perovskite/GaAs nanowire diodes

Halide perovskites have dominated the field of photovoltaics in the past decade with record-breaking efficiencies demonstrated very recently. Likewise, III-V semiconductors represent the state-of-the-art in photovoltaics, being the model system of photovoltaic structure engineering. Herein, we investigate the possibility of using GaAs as an Electron Transporting Layer (ETL), substituting conventional ETLs in halide perovskite photovoltaics. We demonstrate our hypothesis on hybrid CH3NH3PbI3 perovskite/GaAs nanowire (NW) heterostructures, specifically choosing GaAs in its NW form to enhance the electrical contact area between the two materials. The thus obtained heterostructures exhibit a characteristic diode response with improved electrical characteristics when n-doped GaAs NWs are employed. These initial results, which are promising in terms of III-V/perovskite heterojunctions, can potentially lead to efficient CH3NH3PbI3/GaAs NW photovoltaics.