  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.
