Electronic, thermoelectric, transport and optical properties of MoSe2/BAs van der Waals heterostructures

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.