Theoretical design of AIS-BS vdW heterobilayer for a promoted light energy utilization

Van der Waals (vdW) heterostructures assembled by different atomically layers have demonstrated a wide range of fascinating phenomena and novel applications in the fields of optoelectronics and photovoltaics. Exploring the interlayer coupling and their correlation effects is paramount for designing novel heterostructures with desirable properties. In order to achieve a higher photoelectric conversion efficiency, carriers should be separated in space. The coulomb interaction in intrinsic 2D materials often exceeds the driving force of charge transfer which will result in a fast recombination. Experiments have confirmed that it is feasible to adjust the band structure through heterogeneous structures to improve the performance of optoelectronic devices or photocatalysts. Based on the density functional theory, this work combines monolayer AlS and BS through vdW interaction to obtain a heterostructure with well-defined type-II alignment. It proves from different aspects that AlS-BS heterostructure can meet ideal criteria for water splitting and solar cells. The results reveal that the electric field can regulate the band alignment between type-I and type-II, while the strain can maintain the heterostructure in a relatively wide range of type-II. Therefore, the carriers can be effectively separated in space and the predicted efficiency of AlS-BS when strain BS can be as high as similar to 20.7%. This theoretical survey provides a flexible and feasible approach for composites applied in water splitting and solar cells.

Automated summary

Research on Van der Waals heterostructures focuses on assembly, interlayer coupling, and correlation effects to design novel structures with desirable properties for improved photoelectric conversion efficiency. Adjusting band structure through heterogeneous structures to enhance performance of optoelectronic devices or photocatalysts is proven feasible.