PVD Grown p-type SnSe on the hBN Surface with High Field-Effect Mobility

Tin selenide (SnSe) is promised as a candidate for two-dimensional (2D) channels due to the abilities of high carrier mobility, high on-state current, and easy electron or hole doping. However, high-performance p-type SnSe field-effect transistors (FETs) have hardly ever been verified in the laboratory. Here, we directly synthesize SnSe nanosheets on a hexagonal boron nitride (hBN) surface and confirm the formation of a SnSe/hBN structure. According to careful identification, the growth of SnSe lattices originates from the 2 nm thickness amorphous structures, which may be the amorphous SnSe at the SnSe/hBN interface. Through excellent Au Ohmic contact, all p-type FETs made of SnSe grown on hBN achieve the field-effect mobilities above 100 cm2·(V·s)−1 and the maximum of 292 cm2·(V·s)−1 at room temperature, which evidently surpasses other p-type FETs with various channels. This result benefits from the high-quality SnSe channel and the special SnSe/hBN interface. Our research will enable the extension of SnSe applications in monolithic 3D integration.