Electronic, thermoelectric, transport and optical properties of MoSe2/BAs van der Waals heterostructures
Yi Li, Zhen Feng, Qian Sun, Yaqiang Ma, Yanan Tang, Xianqi Dai
Abstract
The density functional theory (DFT) calculations were performed to systematically study the geometrical, electronic, thermoelectric, transport and optical properties of MoSe2/BAs van der Waals heterostructures (vdWHs). The different MoSe2 and BAs stacking configurations effect hardly on the band structure. The MoSe2/BAs vdWHs possesses excellent dynamical, thermal and mechanical stability, with a direct bandgap of 1.04 eV and type-I band alignment. The Seebeck coefficient and ZT suggest the possibility of MoSe2/BAs vdWHs for thermoelectric applications. The in-plane strains and external electric field can modulate the band structure to achieve the transition from type-I to type-II band alignment, and the direct band gap feature remains preserved. Under the in-plane strains and external electric field, one can find a remarkably high optical absorption coefficient (~105 cm−1) in the visible-ultraviolet region and the red shift in the optical absorption spectrum. Its high energy conversion efficiency of 20.08% making the heterostructure extremely potential in solar energy harvesting of low-dimensional excitonic solar cells. These properties of MoSe2/BAs vdWHs show their promising applications in optoelectronic, nanoelectronic and thermoelectronic fields.