Zn空位缺陷ZnS的电子状态、磁性质与光学性质研究

Electronic states,magnetic and optical properties of Zn vacant ZnS

基于密度泛函理论第一性原理,研究了Zn空位缺陷对ZnS半导体材料电子状态、磁性质和光学性质的影响.结果表明Zn空位缺陷浓度为6.25%时,ZnS半导体材料仍呈直接带隙型能带结构,带隙较本征ZnS半导体增大了6.4%,达到2.19 eV.缺陷体系s态、p态电子主要在距离费米能量较近的区域产生能带,数量较少;Znd态电子主要在距离费米能量较远的区域产生能带.Zn空位缺陷对ZnS半导体材料是一种空穴型掺杂,Zn空位会增加ZnS的空穴型载流子浓度.其价带空穴具有较大有效质量,导带电子具有较小有效质量,Zn空位缺陷ZnS不显示磁性.Zn空位缺陷ZnS半导体材料210 nm附近介电吸收峰强度降低,170 nm附近介电吸收峰消失,100 nm波长附近出现了较弱的介电吸收峰.

Influences of Zn vacancy defect on electronic states, magnetic and optical properties of ZnS semiconductor material are investigated by density functional theory first principle. Results show that when the concentration of Zn vacancy defect is 6.25%, ZnS semiconductor material still exhibits a direct band gap structure. Compared with the intrinsic ZnS semiconductor, the band gap is increased by 6.4%,reaching 2.19 eV. The s and p state electrons of defect system form the energy bands near Fermi energy,few in number, and Zn d electrons form the energy bands far from Fermi energy. The Zn vacancy for ZnS semiconductor is a kind of hole doping type and the hole carrier concentration can be increased by Zn vacancy. Its hole carriers within the valence bands are heavy and the electron carriers within the conduction bands are light. Zn vacant ZnS does not show magnetism. The dielectric absorption peak intensity of Zn vacant ZnS semiconductor near 210 nm decreases, the dielectric absorption peak near 170 nm disappears and a weaker dielectric absorption peak near 100 nm emerges.