Here, we investigated electronic and optical properties of AlAs/SiH heterostructure by using first principle. It is demonstrated that the AlAs/SiH heterostructure is indirect type-Ⅱ bandgap heterostructure with bandgap of 2.395 eV. The work functions of monolayers and heterostructure are calculated and the interface charge transfer is theoretically analyzed. The charge density difference indicates that electrons flow from SiH monolayer to AlAs monolayer, which is consistent with theoretical results of the work functions analysis. The bandedge of AlAs/SiH heterostructure straddle the redox potential of the water in pH 0 to 14, which means that AlAs/SiH has photocatalytic activity in different water environments. Furthermore, the bandgap and absorption coefficient of heterostructure can be well adjusted by changing the interfacial strain. We also found through calculation that AlAs/SiH heterostructure has an absorption peak of 2.2 × 10⁵ cm⁻¹ in the visible region. At −2% compressive stress, AlAs/SiH heterostructure have a peak value of 2.5 × 10⁵ cm⁻¹ at 3.2 eV. At 4% tensile stress, absorption spectrum can span the whole visible region. These fascinating properties indicate that AlAs/SiH heterostructure is a highly efficient photocatalyst.

在这里，我们利用第一性原理研究了 AlAs/SiH 异质结构的电子和光学性质。结果表明，AlAs/SiH异质结构为间接带隙Ⅱ型异质结构，带隙为2.395 eV。计算了单层和异质结构的功函数，并从理论上分析了界面电荷转移。电荷密度差异表明电子从SiH单层流向AlAs单层，这与功函数分析的理论结果一致。AlAs/SiH 异质结构的带边跨越了pH 0 到 14 的水的氧化还原电位，这意味着 AlAs/SiH 在不同的水环境中具有光催化活性。此外，带隙和通过改变界面应变可以很好地调整异质结构的吸收系数。我们还通过计算发现AlAs/SiH异质结构在可见光区具有2.2×10 ⁵ cm^-1的吸收峰。在 -2% 的压缩应力下，AlAs/SiH 异质结构 在 3.2 eV 处具有 2.5 × 10⁵ cm^-1的峰值。在 4% 的拉伸应力下，吸收光谱可以跨越整个可见光区。这些迷人的特性表明，AlAs/SiH 异质结构是一种高效的光催化剂。