采用基于密度泛函理论(DFT)的第一性原理方法,在广义梯度近似(GGA)框架下,研究了纯净闪锌矿 ZnS-B3和 Na 掺杂 ZnS 后的晶体结构、电子结构和光学性质.详细分析了不同 Na 掺杂浓度对 ZnS的晶格常数、电子态密度和能带结构的影响,讨论了费米能级附近的电子组态对 ZnS 光学性质的影响.结果表明,掺杂 Na 对 ZnS 光学性能有极大的影响,当Na 离子掺杂浓度为6.25%(原子分数)时,表现出较好的综合光学性质;当掺杂浓度为12.5%(原子分数)时,体系有效负电荷离子浓度增加,S3p 态穿过费米能面,引起 S3p 态电子产生跃迁,在低能量红外区域产生新介电峰,引起光吸收,降低了 ZnS 材料的透红外性能.理论预测结果与文献报道的实验结果相吻合.
The crystal structures,electronic structures and optical properties of Na doping zincblende (ZnS-B3) system (Zn(1 -x )Nax S (x =0,0.0625,0.125))were calculated by using first-principles calculation based on the density functional theory (DFT)within the framework of generalized gradient approximation (GGA).The equilibrium lattice constant,electronic structure including the density of state and band structure of Zn(1 -x ) Nax S (x =0,0.0625,0.125 )were discussed in detail.The effects of the electron configuration around Fermi level on optical properties of Na doped-ZnS materials were analysized theoretically.The calculated results re-vealed that Na doping played an important role in the optical properties of ZnS-B3.The Na2 S doped-ZnS materi-als showed good comprehensive optical properties when the doping concentration of Na+ ion was at 6.25at%, while the concentration of effective negative charge increases when the doping concentration of Na+ ion was at 12.50at%,and the S3p electron stateed cross the Fermi-level and transited to high energy level.New dielectric peak presented in infrared spectra with low energy level and increased the light absorption coefficient,thus de-creased the transmission coefficient of ZnS materials.Present calculated results agree considerably with the ex-periment results in available literatures.