Stacking-Mediated Type-I/Type-II Transition in Two-Dimensional MoTe2/PtS2 Heterostructure: A First-Principles Simulation

Recently, a two-dimensional (2D) heterostructure has been widely investigated as a photocatalyst to decompose water using the extraordinary type-II band structure. In this work, the MoTe2/PtS2 van der Waals heterostructure (vdWH) is constructed with different stacking structures. Based on density functional calculations, the stacking-dependent electronic characteristic is explored, so that the MoTe2/PtS2 vdWH possesses type-I and type-II band structures for the light-emitting device and photocatalyst, respectively, with decent stacking configurations. The band alignment of the MoTe2/PtS2 vdWH is also addressed to obtain suitable band edge positions for water-splitting at pH 0. Furthermore, the potential drop is investigated, resulting from charge transfer between the MoTe2 and PtS2, which is another critical promotion to prevent the recombination of the photogenerated charges. Additionally, the MoTe2/PtS2 vdWH also demonstrates a novel and excellent optical absorption capacity in the visible wavelength range. Our work suggests a theoretical guide to designing and tuning the 2D heterostructure using photocatalytic and photovoltaic devices.

Automated summary

In this study, the electronic characteristics and properties of a MoTe2/PtS2 van der Waals heterostructure (vdWH) were investigated through density functional calculations. The study found that the stacking structures of the heterostructure have a significant impact on the band structure, and proposed suitable stacking configurations for both photocatalytic and light-emitting device applications. The band alignment and potential drop were also studied to prevent charge recombination, and the heterostructure showed excellent optical absorption capacity in the visible wavelength range. The research provides a theoretical guide for designing and controlling 2D heterostructures for photocatalytic and photovoltaic devices.