Recently, van der Waals (vdW) heterostructures have attracted extensive research interest due to their extraordinary properties and potential applications in photovoltaic and photocatalytic devices. Here, we propose As/CdO vdW heterostructure with compelling optical and photocatalytic properties which has been studied by means of first-principles calculations. The stability of the heterostructure is verified by calculating the binding energy and ab-initio molecular dynamics simulations. We demonstrate that the As/CdO vdW heterostructure possesses a direct band gap of about 1.96 eV with type-II (staggered) band alignment, which can effectively reduce the recombination of photogenerated electron-hole pairs. Compared with two isolated parts, As/CdO vdW heterostructure shows suitable band edge positions and high absorption efficiency in the visible and ultraviolet light regions, making it a good candidate for optical devices and photocatalytic water splitting. The calculated higher carrier mobility of holes and electrons along the armchair direction are 932.510 cm² V⁻¹ s⁻¹ and 90.808 cm² V⁻¹ s⁻¹, respectively. Biaxial strain can modulate the electronic structure and optical characteristics of As/CdO vdW heterostructure. In particular, compressive strain shows robust type-II band alignment and improve the optical performance of As/CdO vdW heterostructure in the visible light region. Our results are beneficial for designing optoelectronic and photocatalytic devices.

最近，范德华（vdW）异质结构由于其非凡的性能和在光伏和光催化设备中的潜在应用而引起了广泛的研究兴趣。在这里，我们建议 As/CdO vdW通过第一性原理计算研究了具有引人注目的光学和光催化性能的异质结构。通过计算结合能和从头算分子动力学模拟来验证异质结构的稳定性。我们证明 As/CdO vdW 异质结构具有约 1.96 eV 的直接带隙，具有 II 型（交错）带排列，可以有效减少光生电子 - 空穴对的复合。与两个孤立的部分相比，As/CdO vdW 异质结构在可见光和紫外光区域显示出合适的带边位置和高吸收效率，使其成为光学器件的理想选择和光催化分解水。计算的空穴和电子沿扶手椅方向的较高载流子迁移率分别为932.510 cm ²  V ^-1  s ^-1和90.808 cm ²  V ^-1  s ^-1。双轴应变可以调节 As/CdO vdW 异质结构的电子结构和光学特性。特别是，压缩应变显示出稳健的 II 型能带对齐，并改善了可见光区域中 As/CdO vdW 异质结构的光学性能。我们的结果有利于设计光电和光催化设备。