Optoelectronic Properties of Hexagonal Boron Nitride Shielded Molybdenum Diselenide/Black-Phosphorus Based Heterojunction Field Effect Transistor

Abstract

Herein, we report the fabrication of a novel heterojunction field-effect transistor (HJFET) based on two-dimensional graphene (Gr), molybdenum diselenide (MoSe2), and black phosphorus (BP) that is shielded using hexagonal boron nitride to prevent device degradation. We perform electrical and optoelectronic characterizations of Gr/n-MoSe2 and Gr/n-MoSe2/p-BP heterojunctions. Heterojunction n-MoSe2/p-BP exhibits a potential barrier at the interface, which allows the use of BP as a top-gate contact to adjust the electrical and optoelectronic performances of the Gr/n-MoSe2 heterojunction. In the absence of a gate voltage, the Gr/n-MoSe2 and Gr/n-MoSe2/p-BP heterojunctions indicate photoresponsivity (Rλ) and specific detectivity (D*) of 1.77 AW−1 and 1.4 × 1010 cmHz1/2W−1, and 0.8 AW−1 and 0.3 × 1010 cmHz1/2W−1, respectively. The Gr/n-MoSe2 junction field-effect transistor with p-BP as gate contact demonstrates the best optoelectronic performance with high stability in terms of photoresponsivity Rλmax = 3.37 AW−1 and specific detectivity D*max = 3.16 × 1010 cmHz1/2W−1, rendering it extremely promising for photodetection applications.