二维Ag2S的电子和光电性能的第一性原理研究.

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. [ABSTRACT FROM AUTHOR]