论文部分内容阅读
采用基于密度泛函理论的第一性原理赝势平面波方法,对闪锌矿结构CdS和CdS∶M(M=Mg,Ni)几何结构、能带结构、电子态密度和光学性质进行了系统的研究。几何结构研究对掺杂后体系晶格常量进行了优化计算,结果表明Mg和Ni原子掺入CdS后晶格常量均减小,晶格发生局部畸变。进一步研究了掺杂对体系电子结构的影响,能带结构和电子态密度分析表明由于Ni 3d电子的引入使CdS∶Ni成为半金属铁磁半导体,而Mg 3s电子的引入CdS∶Mg带隙变宽。另外,体系掺杂后,吸收系数分析表明掺杂导致吸收峰在可见光波长区域变化显著,且掺Ni导致吸收峰进一步向长波方向移动。
The geometrical structures, band structures, electronic density of states and optical properties of CdS and CdS: M (M = Mg, Ni) sphalerite have been studied systematically using the first principles pseudopotential plane wave method based on density functional theory the study. The geometrical structure of the doped system is optimized. The results show that the lattice constants of both Mg and Ni atoms decrease and the lattice distortion occurs after CdS implantation. The influence of doping on the electronic structure of the system was further studied. The band structure and electronic density of states analysis showed that the introduction of Ni 3d electron made CdS: Ni into semimetallic ferromagnetic semiconductor, while the introduction of Mg 3s into CdS: Mg bandgap width. In addition, after the system is doped, the absorption coefficient analysis shows that the doping leads to significant change of the absorption peak in the visible wavelength region, and the doping with Ni causes the absorption peak to move further in the long wavelength direction.