A recently predicted hexagonal SiSe₂ monolayer is investigated using first-principles calculations to investigate the structural, electronic, transport and optical properties. The electronic structure reveals indirect characteristics with a bandgap of 0.48 eV and 1.17 eV using PBE and HSE06 functional respectively with a valence band in between Γ-M and conduction band at M point. Further, to tune the electronic bandgap, the monolayer is subjected to mechanical strain. The electronic transport show higher electron carrier mobility of about 1.29 × 10³ cm²V⁻¹sec⁻¹ and 19.64 × 10³ cm²V⁻¹sec⁻¹ along both x- and y-direction respectively as compared to hole. The higher electron mobility as compared to hole is attributed to small values of electron effective mass of about 0.298 m₀ and 0.382 m₀ along x- and y-direction respectively. The optical properties were also studied under strained conditions and a high absorption coefficient of the order of 10⁴ cm⁻¹ is observed. Small changes in the absorption can be observed on application of biaxial strain. Our study suggests its potential use in optoelectronics and flexible nano-devices for the detection and absorption in the near infrared, visible and ultraviolet regions.

使用第一性原理研究了最近预测的六角形SiSe ₂单层，以研究结构，电子，传输和光学性质。电子结构显示间接特性，分别使用PBE和HSE06的带隙分别在Γ-M和M点的导带之间的带隙为0.48 eV和1.17 eV。此外，为了调谐电子带隙，使单层经受机械应变。电子传输显示出较高的电子载流子迁移率，约为1.29×10 ³ cm ² V ^-1秒^-1和19.64×10 ³ cm ² V ^-1秒^-1与孔相比分别沿x和y方向。与空穴相比，较高的电子迁移率归因于沿x方向和y方向分别为约0.298m ₀和0.382m ₀的电子有效质量的较小值。还在应变条件下研究了光学性质，并且观察到约10 ⁴  cm ^-1的高吸收系数。在施加双轴应变时可以观察到吸收的微小变化。我们的研究表明其在光电和柔性纳米器件中的潜在用途，可用于近红外，可见光和紫外光区域的检测和吸收。