Quantum Transport and Spectroscopy of 2D Perovskite/Graphene Heterostructures

Understanding the quantum transport properties of (Two-dimensional) 2D perovskite heterostructures is key to interpreting their electronic performance and promoting optoelectronic devices. Here, it is shown that clear Shubnikov-de Hass oscillation appears in the heterostructure of monocrystalline 2D perovskites and graphene, thanks to the clean interface. An efficient charge transfer between perovskite nanosheets and graphene is found, facilitating the separation of electrons and holes at the interface. The relation between the charge transfer efficiency and microscopic interface structures is quantitatively described. The evidence of photo-assisted transport from the photo-response of magnetoresistance is revealed, which happens between Landau levels of two graphene layers mediated by hot carriers in the perovskite layer, overcoming the barrier from the organic layers in the Ruddlesden-Popper perovskite phase. These results provide a picture to understand the transport behavior of 2D perovskite/graphene heterostructure and a reference for the controlled design of interfaces in perovskite optoelectronic devices.