Tunable Schottky barrier in graphene/XAg4Y (X, Y = S, Se, Te) heterostructures

Abstract

Two-dimensional (2D) metal-semiconductor heterostructures have attracted extensive interest in future integrated electronics and energy-related applications. Here, the modulated electronic properties and interface contact of G/XAg4Y (X, Y = S, Se, and Te) heterostructures are investigated via first-principles methods. G/XAg4Y with G/SAg4Y and G/SeAg4Y are n-type Schottky contacts whose Φn range from 1.07 to 1.22 eV, while those with G/TeAg4Y are p-type Schottky contacts whose Φp range from 1.17 to 1.20 eV. Because of interfacial charge transfer, the n-type Schottky contacts of G/XAg4Y with G/SAg4Y and G/SeAg4Y evolve to p-type Schottky contacts by applying positive external electric fields or reducing the interlayer distances. Oppositely, the p-type Schottky contacts of the G/XAg4Y with the G/TeAg4Y change to n-type Schottky contacts by applying a negative external electric field or increasing the interlayer distances. These predicted results show that G/XAg4Y heterostructures possess interlayer-distance and electric-field dependent Schottky barrier height, which possesses potential in future integrated electronics and energy-related applications.