Due to the atomic level thickness and novel properties, two-dimensional (2D) materials have received extensive attention on the research and application of future nanodevices. In this paper, the mechanical and electronic properties of $\alpha \text{−}{M}_2{X}_3$ ($M$ = Ga, In; $X$ = S, Se) monolayers are studied to explore their applications in 2D electronic devices. First-principles calculations based on density functional theory indicate that these four $\alpha \text{−}{M}_2{X}_3$ monolayers are all semiconductors and possess Young's modulus of less than 100 ${\mathrm{N}\mathrm{m}}^{-1}$ with a deformation range up to about 30%. In addition, the carrier mobility of the $\alpha \text{−}{M}_2{X}_3$ monolayer exceeds 600 ${\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$ and remains high under strain. In particular, because the band edge shifts under compressive strain, the electron mobility of the $\alpha \text{−}{\mathrm{Ga}}_2{\mathrm{S}}_3$ monolayer increases to about 1800 ${\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$ at $-3\%$ strain, which is approximately three times the value without strain. The excellent ductility and strain-promoted electronic properties make the 2D $\alpha \text{−}{M}_2{X}_3$ promising candidates for the application of flexible electronic devices.

中文翻译：

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α-M2X3(M=Ga, In;X=S, Se)单层的机械和电子特性

由于原子级厚度和新颖的特性，二维（2D）材料在未来纳米器件的研究和应用中受到广泛关注。在本文中，机械和电子特性$\alpha \text{-}{米}_2{X}_3$($米$= 镓，在；$X$= S, Se) 单层被研究以探索它们在二维电子器件中的应用。基于密度泛函理论的第一性原理计算表明，这四个$\alpha \text{-}{米}_2{X}_3$单层都是半导体，杨氏模量小于 100${\mathrm{ñ}\mathrm{米}}^{-1}$变形范围可达 30% 左右。此外，载流子迁移率$\alpha \text{-}{米}_2{X}_3$单层超过600${\mathrm{厘米}}^2{\mathrm{五}}^{-1}{\mathrm{s}}^{-1}$并在压力下保持高位。特别是，由于带边在压缩应变下移动，电子迁移率$\alpha \text{-}{镓}_2{\mathrm{小号}}_3$单层增加到约1800${\mathrm{厘米}}^2{\mathrm{五}}^{-1}{\mathrm{s}}^{-1}$在$-3\%$应变，大约是没有应变时的三倍。优异的延展性和应变促进的电子特性使二维$\alpha \text{-}{米}_2{X}_3$有望成为柔性电子设备应用的候选者。