First-principles predication of facet-dependent electronic and optical properties in InSe/GaAs heterostructure with potential in solar energy utilization

Building two-dimensional (2D) heterostructure emerges novel properties, attracting great attention in materials science. Here, we design InSe/GaAs heterostructures and explore their novel photoelectric properties using first-principles method. Heterostructures have been shown to be direct bandgap semiconductors with type-II band alignment. Meanwhile, the electronic properties of heterostructures are not only sensitive to stacking model but also strongly dependent on the facet of GaAs contacting InSe. The heterostructures, with As-facet contacting InSe, are confirmed to be preeminent photocatalyst for water splitting. While formed with Ga-facet, heterostructures can be used as appropriate photovoltaic material. All heterostructures possess broad absorption range, with high absorption coefficients (similar to 10(5)). Besides, the carrier mobilities are outstanding. Therefore, the above prediction results make the InSe/GaAs heterostructures promising to be used in solar energy utilization. (C) 2020 Elsevier B.V. All rights reserved.