Comparative Study of Blue Phosphorus-MoTe2/WTe2 van der Waals Heterostructures on Electronic Structures and Band Realignment

Herein, blue phosphorus (BP) and monolayer MoTe2/WTe2 are blended to obtain type-II band alignment heterostructures based on the density functional theory (DFT). The first-principles calculations are performed to explore the interlayer coupling effects and the bands realignment of BP-MoTe2/WTe2 when the external strain is imposed. It is proved that the bandgap variation of BP-MoTe2/WTe2 heterostructures exhibits interesting responses to the applied external strain compared with freestanding structures, and an obvious promoted light adsorption in solar spectrum range is observed in BP-MoTe2. The band structures reveal that the photoinduced electrons/holes are transferred to the conduction/valence band of BP from the valence/conduction band of MoTe2/WTe2, respectively. The calculations also confirm that BP-MoTe2 is more suitable for solar energy utilization in comparison with BP-WTe2, because it can realize a better response to solar energy and a prominent carriers' separation. In brief, a convictive theoretical approach is presented to reveal the evolution of water splitting activity achieved by BP-MoTe2/WTe2 heterostructures.