Ultrafast carrier response of CH 3 NH 3 PbI 3 /MoO 3 /graphene heterostructure for terahertz waves

Abstract Ultrafast carrier response of perovskite/MoO 3 /graphene heterostructure was investigated by optical-pump terahertz (THz) probe spectroscopy. The high work function of MoO 3 changes the tunable graphene Fermi level via hole doping. Compared with monolayer graphene, it generates a more negative photoconductivity and enables ultra-fast THz functional manipulation. The subsequent THz signal decrease is related to hot-carrier cooling and the carrier concentration contributed by the CH 3 NH 3 PbI 3 layer. The charge transfer and recombination reduce the positive conductance of the hybrid structure relative to that of neat CH 3 NH 3 PbI 3 .