Bond relaxation and electronic properties of two-dimensional Sb/MoSe2 and Sb/MoTe2 van der Waals heterostructures

Abstract

Van der Waals heterostructures have recently garnered interest for application in high-performance photovoltaic materials. Consequently, understanding the basic electronic characteristics of these heterostructures is important for their utilisation in optoelectronic devices. The electronic structures and bond relaxation of two-dimensional (2D) Sb/transition metal disulfides (TMDs, MoSe2, and MoTe2) van der Waals heterostructures were systematically studied using the bond-charge (BC) correlation and hybrid density functional theory. We found that the Sb/MoSe2 and Sb/MoTe2 heterostructures had indirect band gaps of 0.701 and 0.808 eV, respectively; further, these heterostructures effectively modulated the band gaps of MoSe2 (1.463 eV) and MoTe2 (1.173 eV). The BC correlation revealed four bonding and electronic contributions (electron-holes, antibonding, nonbonding, and bonding states) of the heterostructures. Our results provide an in-depth understanding of the Sb/TMD van der Waals heterojunction, which should be utilised to design 2D metal/semiconductor-based devices.