二维Ag2S的电子和光电性能的第一性原理研究

二维Ag₂S是一种具有间接宽带隙的半导体材料，由其在平面内和平面外具有独特的力学性质，因此受到了人们的广泛关注.本文基于密度泛函理论进行了第一性原理计算，研究了二维Ag₂S的电子、光学性质的变化.二维Ag₂S具有较强的方向各异性，通过不同浓度的O取代S替换掺杂，发现随着O浓度的增加，带隙值出现先增大后减小的现象;由于O元素的引入，使二维Ag₂S结构对称性降低，引起能带及光吸收、光反射的分布离散化.y方向4.56～5.36 e V处光吸收及光反射峰随掺杂浓度增加逐渐减小，且出现明显的蓝移.

First - principles study of electronic and optical properties of two - dimensional Ag2S

Two-dimensional Ag2S is a semiconductor material with an indirect wide band gap. It has received extensive attention due to its unique mechanical properties in and out of plane. In this paper, the electronic and optical properties of two-dimensional Ag2S are studied by first-principles calculations based on density functional theory. The two-dimensional Ag2S has strong directional anisotropy. By replacing S with O at different concentrations, it is found that the band gap value increases first and then decreases with the increase of O concentration. Due to the introduction of O element, the symmetry of the two-dimensional Ag2S structure is reduced, which causes the distribution discretization of energy band, light absorption and light reflection. The light absorption and light reflection peaks at 4.56 ~ 5.36 eV in the y direction gradually decrease with the increase of doping concentration, and there is an obvious blue shift.