SnSe field-effect transistors with improved electrical properties

Low-symmetry two-dimensional (2D) materials, with unique in-plane direction-dependent optical, electrical, and thermoelectric properties, have been intensively studied for their potential application values in advanced electronic and optoelectronic devices. However, since anisotropic 2D materials are highly sensitive to the environmental factors, researches on their high-performance field-effect transistors (FETs) are still limited. Here, we report a high-performance SnSe FET based on a van der Waals (vdWs) heterostructure of SnSe encapsulated in hexagonal boron nitride (hBN) together with graphene contacts. The device exhibits a high on/off ratio exceeding 1 × 10⁹, and a carrier mobility of 118 cm²·V^-1·s^-1. Our work highlights low-symmetry 2D SnSe holds potential to be used for designing excellent electronic devices.