In this work, two dimensional QBi (Q=Si, Ge and Sn) monolayers with P6m2 space group are investigated by using first principle calculations based on the density functional theory. As the first step, the stability of the proposed monolayer materials was examined. Based on our calculations, QBi (Q=Si, Ge and Sn) monolayer structures have proper structural and dynamic stabilities, so they are promising substances to fabricate experimentally. Investigate of electronic structures which confirmed by cohesive energy calculation and phonon dispersion simulation respectively. Evaluating the electronic properties of these materials shows that they are semiconductors with small direct band gaps which can be effectively adjusted by applying compressive and tensile strains. Moreover, based on our optical properties evaluation these monolayer materials show strain tunable optical characteristics in visible region of light. The results of this research reveal that QBi (Q=Si, Ge and Sn) monolayers are promising materials for using in different electro-optical devices especially electromechanical and optical sensors.

在这项工作中，使用基于密度泛函理论的第一性原理计算研究了具有 P6m2 空间群的二维 QBi（Q=Si、Ge 和 Sn）单层。作为第一步，检查了所提出的单层材料的稳定性。根据我们的计算，QBi（Q=Si、Ge 和 Sn）单层结构具有适当的结构和动态稳定性，因此它们是有前途的实验制造物质。研究分别通过内聚能计算和声子色散模拟证实的电子结构。评估这些材料的电子特性表明它们是具有小直接带隙的半导体，可以通过施加压缩和拉伸应变进行有效调整。而且，根据我们的光学特性评估，这些单层材料在可见光区域显示出应变可调光学特性。这项研究的结果表明，QBi（Q=Si、Ge 和 Sn）单分子层是很有前途的材料，可用于不同的电光器件，尤其是机电和光学传感器。