Abstract The effect of biaxial strains e b and electric field E on the electronic structure and optical properties of Janus monolayer PtSSe was studied by Density Functional Theory (DFT). A reasonable band gap of PtSSe was found to be 1.547 eV. In the infrared region, both biaxial strains and electric fields result in noticeable enhancement of the electronic structure as well as optical properties of PtSSe. Especially, under biaxial strains, the change of PtSSe band gap obeys the form of an asymmetric concave down parabola. This result confirms the existence of a maximum PtSSe band gap under biaxial strains e b and the possibility of tuning PtSSe band gap to fit the requirement of the optoelectronic devices. The absorption rate in the visible light region of Janus monolayer PtSSe increases sharply and can be altered by strain engineering. Biaxial strain not only alters the absorption intensity but can also significantly shift the position of these absorption peaks. The present study provides additional information about the strain and electric field-induced electronic structure and optical properties of Janus monolayer PtSSe, which should be taken into account for better PtSSe-based devices.

中文翻译：

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外电场和应变下的 Janus 单层 PtSSe：电子结构和光学性质的第一性原理研究

摘要 采用密度泛函理论(DFT) 研究了双轴应变eb 和电场E 对Janus 单层PtSSe 电子结构和光学性质的影响。发现 PtSSe 的合理带隙为 1.547 eV。在红外区域，双轴应变和电场均显着增强了 PtSSe 的电子结构和光学特性。特别是在双轴应变下，PtSSe 带隙的变化服从不对称凹下抛物线的形式。该结果证实了双轴应变 eb 下最大 PtSSe 带隙的存在以及调整 PtSSe 带隙以满足光电器件要求的可能性。Janus 单层 PtSSe 在可见光区域的吸收率急剧增加，并且可以通过应变工程来改变。双轴应变不仅会改变吸收强度，还会显着改变这些吸收峰的位置。本研究提供了关于 Janus 单层 PtSSe 的应变和电场诱导的电子结构和光学特性的额外信息，这些信息应该被考虑到更好的 PtSSe 器件。