In this work, the influence of biaxial strain on electronic, optical, and effective masses characteristics of Janus MSSe (M = Mo, W) have been investigated through first-principles calculations as implemented in WIEN2k package. From the obtained results, we remark that MoSSe and WSSe monolayers exhibit, respectively, a direct and indirect bandgap transition at equilibrium. Our achieved results demonstrate that the biaxial strain fundamentally alters the electronic states of Janus MSSe monolayers, and mainly, a semiconductor-metal transition phase has been determined to occur at a biaxial strain ratio of 12%. Moreover, it has been revealed that both electrons and holes effective masses of MSSe monolayers can be tuned by biaxial strain. For the optical properties of Janus monolayers, the polarization direction of the incident light plays a vital role in defining the light absorption domain. The MSSe Janus monolayers are shown to have a wide range of absorption spectrum, including the visible light domain with perpendicular polarized light. Furthermore, our computations of the dielectric function indicate that the optical responses of Janus monolayers MoSSe and WSSe strongly depend on the applied strain ratio; particularly, for the high photon energy domain. Overall, the findings revealed that both Janus MoSSe and WSSe monolayers could be potential materials for applications in optoelectronics.

在这项工作中，通过在 WIEN2k 包中实施的第一性原理计算，研究了双轴应变对 Janus MSSe (M = Mo, W) 的电子、光学和有效质量特性的影响。根据获得的结果，我们注意到 MoSSe 和 WSSe 单层分别表现出平衡时的直接和间接带隙跃迁。我们取得的结果表明，双轴应变从根本上改变了 Janus MSSe 单层的电子态，主要是已确定半导体-金属过渡相以 12% 的双轴应变比发生。此外，研究表明 MSSe 单层的电子和空穴有效质量都可以通过双轴应变进行调节。对于 Janus 单层的光学特性，领域。MSSe Janus 单层显示具有广泛的吸收光谱，包括具有垂直偏振光的可见光域。此外，我们对介电函数的计算表明，Janus 单层 MoSSe 和 WSSe 的光学响应强烈依赖于施加的应变比；特别是对于高光子能量域。总体而言，研究结果表明，Janus MoSSe 和 WSSe 单层都可能成为光电子学应用的潜在材料。