Eu掺杂ZnO结构光电性质的第一性原理及实验研究

FIRST-PRINCIPLES AND EXPERIMENTAL STUDY ON THE ELECTRONIC AND OPTICAL PROPERTIES OF Eu DOPED ZnO STRUCTURE

采用基于密度泛函理论的第一性原理平面波超软赝势方法,计算了稀土Eu掺杂ZnO结构的能带结构、态密度以及光学性质,并与未掺杂体系进行了对比分析.结果表明,Eu掺杂的ZnO结构引入了由Eu贡献的导电载流子,体系的电导率增强,Fermi能级上升进入导带并表现n型导电性.光学性质上,掺杂结构在低能区域的吸收系数要比纯净ZnO高.在随后的实验部分,通过烧结法制备了Eu掺杂的ZnO粉体,并利用SEM,XRD和光致发光光谱(PL)表征了掺杂前后ZnO结构的变化.结果表明,Eu的掺入使得ZnO的晶格常数变大,结晶程度变弱.

Pure and Eu doped ZnO were calculated by first-principles full potential linearized augmented plane wave ultra-soft pseudo-potential method to investigate band structures, density of states （DOS） and optical properties of the structures. The results show that the conduction bands gen- erate conductive carriers introduced by impurity atom of Eu. The electrical conductivity of the system is improved and the Fermi levels shift upward into the conduction band and show n-type conductivity. The absorption coefficient of Eu doped ZnO are higher than that of pure ZnO in low energy region. In the experiment part, pure and Eu doped ZnO powder were prepared through sintering method and the corresponding properties of the samples were investigated by XRD, SEM and photoluminescence （PL） spectra, which show that the lattice constants of ZnO become larger and crystallization turn worse after doping.