First-principles study on electronic states of In(2)Se(3)/Au heterostructure controlled by strain engineering

The development of low-dimensional multifunctional devices has become increasingly important as the size of field-effect transistors decreases. In recent years, the two-dimensional (2D) semiconductor In(2)Se(3) has emerged as a promising candidate for applications in the fields of electronics and optoelectronics owing to its remarkable spontaneous polarization properties. Through first-principles calculations, the effects of the polarization direction and biaxial tensile strain on the electronic and contact properties of In(2)Se(3)/Au heterostructures are investigated. The contact type of In(2)Se(3)/Au heterostructures depends on the polarization direction of In(2)Se(3). The more charge transfers from the metal to the space charge region, the biaxial tensile strain increases. Moreover, the upward polarized In(2)Se(3) in contact with Au maintains a constant n-type Schottky contact as the biaxial tensile strain increases, with a barrier height Φ(SB,n) of only 0.086 eV at 6% strain, which is close to ohmic contact. On the other hand, the downward polarized In(2)Se(3) in contact with Au can be transformed from p-type to n-type by applying a biaxial tensile strain. Our calculation results can provide a reference for the design and fabrication of In(2)Se(3)-based field effect transistors.