The investigations of quantum spin Hall effect and the edge states manipulation of two dimensional topological insulators are very salient for the practical applications and fundamental sciences. The high thermoelectric efficiency of these materials has also been confirmed, recently. So, in this study the first-principles calculations are implemented based on density functional theory in the presence of spin orbit interaction, to evaluate the topological phase transition and thermoelectric performance of XBi (X = Sc, Y) monolayers under in-plane strains. It is found that the compressive in-plane strains and spin orbit interaction, which host considerable effects on the electronic structure, can cause the topologically nontrivial phase and high thermoelectric performance. The topological state of XBi monolayers is confirmed with the Z₂ topological invariant calculation. These results provide these monolayers for the novel thermoelectric and nanoelectronics quantum devices and topological phenomena. Also some optical properties of XBi monolayers are calculated and investigated under in-plane strains. The results show the considerable transparency and reflectivity of these monolayers near zero energy.

二维自旋霍尔效应的量子自旋霍尔效应和边沿状态操纵的研究对于实际应用和基础科学具有重要意义。最近还证实了这些材料的高热电效率。因此，在本研究中，基于自旋轨道相互作用的密度泛函理论，对第一性原理进行了计算，以评估面内应变下XBi（X = Sc，Y）单层的拓扑相变和热电性能。研究发现，压缩面内应变和自旋轨道相互作用会对电子结构产生重大影响，它们会引起拓扑上无关紧要的相位和较高的热电性能。XBi单层的拓扑状态由Z ₂拓扑不变性计算。这些结果为新颖的热电和纳米电子量子器件和拓扑现象提供了这些单层。还计算了XBi单层的一些光学性质，并在面内应变下进行了研究。结果表明，这些单层接近零能量时具有相当高的透明度和反射率。