第一性原理研究稀土掺杂ZnO结构的光电性质

基于密度泛函理论的第一性原理平面波超软赝势方法,运用Castep计算分析了Er, Gd两种稀土元素掺杂的ZnO结构, 对本征ZnO和掺杂晶体的能带结构、态密度以及光学性质进行了分析对比. 由掺杂前后的结果分析发现,稀土掺杂的ZnO结构引入了由稀土原子贡献的导电载流子, 增强了体系的电导率, 费米能级上移进入导带. 研究表明由于稀土元素的掺入, ZnO结构在费米能级附近出现了杂质能带, 这是由稀土的4f态电子所形成. 同时, 纯净ZnO与Er-ZnO, Gd-ZnO和(Er, Gd)-ZnO的介电函数虚部有明显的差异. 在光学性质上, 掺杂ZnO在可见光区的吸收系数和反射率都比纯净ZnO高, 能量损失峰出现红移现象. 关键词： ZnO 稀土 掺杂 第一性原理

First principles study on the electronic and optical properties of ZnO doped with rare earth

In this paper we use first-principles full potential linearized augmented plane wave method to investigate the band structure, density of states as well as the optical properties of ZnO, intrinsic and doped separately with Er and Gd. We find that dut to the carriers contributed by the introduced impurity atoms of rare earth (RE), the electrical conductivity of the system is improved and the Fermi level has an upward shift to the conduction band. The data show that due to the doping of RE, there appear the new electron occupied states around the Fermi level. This is formed by the states of Er-4f and Gd-4f. Meanwhile, intrinsic ZnO and doped structures are obviously different. For the optical properties, the absorption coefficient and reflectivity of rare earth doped ZnO are higher than those of intrinsic ZnO in visible region and the energy loss spectra of RE doped ZnO structure present red-shift.