密度泛函理论研究硫族元素取代对单层Ag_(2)S结构和电子性质的影响

Density functional theory study on the effects of chalcogen substitution on structural and electronic properties of single-layer Ag_(2)S

本文利用第一性原理计算讨论了硫族元素掺杂单层Ag_(2)S的缺陷形成能和电子性质.缺陷形成能反映了在富Ag条件下的掺杂更容易.计算得到的带隙、Mulliken布居和态密度展示出了其相应结构的电子性质.与纯单层的Ag_(2)S相比,Se/Te掺杂Ag_(2)S后的带隙显示出其电导率变化不大.基于Mulliken原子和键布居,研究了硫族元素掺杂后Ag_(2)S中的共价性.此外,通过讨论态密度,分析了能级的移动和电子的贡献.

We use the first-principles calculations to discuss the defect formation energy and electronic properties of chalcogen-doped single-layer Ag_(2)S.The defect formation energies reflect that the energetic favorability of doping under Ag-rich condition is recommended.The electronic properties are embodied by the corresponding characters of the band gap,Mulliken populations and density of states.Compared to pure single-layer Ag_(2)S,the band gaps of Ag_(2)S with Se/Te doping reflect that the electrical conductivity is about the same.The Mulliken atomic and bond populations are discussed to investigate the covalency of Ag_(2)S after chalcogen doping.In addition,the shifts of energy levels and the electrons contributions are analyzed by discussing the density of states.