Electrical performance and low frequency noise in hexagonal boron nitride encapsulated MoSe2 dual-gated field effect transistors

Abstract

We demonstrate few-layer molybdenum diselenide (MoSe2) dual-gated field effect transistors (FETs) with few-layer hexagonal boron nitride (hBN) flakes as encapsulation and multilayer graphene as electrical contacts. A high current on/off ratio of up to ∼108, a two-terminal electron mobility of 38.5 cm2/V·s at room temperature, and negligible hysteresis are achieved in hBN encapsulated MoSe2 FETs. Our results also indicate that the flicker (1/f) current noise in hBN encapsulated MoSe2 transistors is governed by Hooge's carrier mobility fluctuation and the normalized current noise in the dual-gated configuration can be dramatically reduced by applying a positive bias on the bottom gate. All these suggest that dual-gated MoSe2 FETs are very promising candidates for sensing applications.