The geometric structure of the BAs/WTe₂ heterojunction was scrutinized by employing ab initio calculations grounded on density functional theory. Multiple configurations are constructed to determine the equilibrium state of the heterojunction with optimal stability. The results show that the H1-type heterojunction with interlayer distance of 3.92 Å exhibits exceptional stability and showcases a conventional Type-II band alignment, accompanied by a direct band gap measuring 0.33 eV. By applying external electric field and introducing strain, one can efficaciously modulate both the band gap and the quantity of charge transfer in the heterojunction, accompanied by the transition of band alignment from Type-II to Type-I, which makes it expected to achieve broader applications in light-emitting diodes, laser detectors and other fields. Ultimately, the heterojunction undergoes a transformation from a semiconducting to a metallic state. Furthermore, the outstanding optical characteristics inherent to each of the two monolayers are preserved, the BAs/WTe₂ heterojunction also serves to enhance the absorption coefficient and spectral range of the material, particularly within the ultraviolet spectrum. It merits emphasis that the optical properties of the BAs/WTe₂ heterojunction are capable of modification through the imposition of external electric fields and mechanical strains, which will expand its applicability and potential for future progression within the domains of nanodevices and optoelectronic apparatus.

中文翻译：

---

用于理论光电器件设计的 BAs/WTe2 异质结构的可调谐电子和光学特性

BAs/WTe ₂异质结的几何结构通过采用从头开始基于密度泛函理论的计算。构建多种配置以确定具有最佳稳定性的异质结的平衡状态。结果表明，层间距离为 3.92 Å 的 H1 型异质结表现出出色的稳定性，并呈现出传统的 II 型能带排列，并伴有 0.33 eV 的直接带隙。通过施加外部电场并引入应变，可以有效地调节异质结的带隙和电荷转移量，伴随着能带排列从Type-II向Type-I的转变，这使得它有望实现更宽的带隙。应用在发光二极管、激光探测器等领域。最终，异质结经历从半导体态到金属态的转变。此外，保留了两个单层各自固有的出色光学特性，BAs/WTe ₂异质结还用于增强材料的吸收系数和光谱范围，特别是在紫外光谱内。值得强调的是，BAs/WTe ₂异质结的光学性质能够通过施加外部电场和机械应变来改变，这将扩大其在纳米器件和光电设备领域的适用性和未来发展的潜力。