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采用基于密度泛函理论(DFT)的总体能量平面波超软赝势法,电子交换关联能结合广义梯度近似(GGA)PW91形式,对Al原子掺杂不同超晶胞ZnO∶AlZn2n-1O2n(n=4,8,16和32)进行几何优化,分析比较了掺杂模型的电子结构及光学性质。结果表明,Al置换Zn位置掺杂容易,随着掺杂摩尔比例(Al∶ZnO)的减小,杂质元素对超晶胞晶格畸变程度减弱,Al和基体ZnO的原子数配比直接影响导电性能。光学性质计算发现,掺杂Al对紫外光波段(100~400nm)影响明显,随着摩尔比例(Al∶ZnO)减少,掺杂材料吸收系数下降,本征吸收边存在紫外光很窄波段内,电子跃迁的轨道能级主要集中于紫外光波段。
Using super soft pseudopotential method based on density functional theory (DFT), the electron exchange correlation can be combined with generalized gradient approximation (GGA) PW91 form to investigate the effect of Al atom doping different supercell ZnO: AlZn2n-1O2n (n = 4, 8, 16 and 32), the electronic structure and optical properties of the doped model were analyzed and compared. The results show that it is easy to doping Zn with Al substitution. With the decrease of the molar ratio of Al (Al: ZnO), the lattice distortion of superlattice cells is weakened by impurity elements. The atomic ratio of Al and matrix ZnO directly affects the conductivity performance. The calculated optical properties show that doped Al has an obvious effect on the ultraviolet (100 ~ 400nm) wavelength range. With the decrease of the molar ratio (Al: ZnO), the absorption coefficient of the doped material decreases and the intrinsic absorption edge exists in a narrow band of UV light. The orbital energy level of the electronic transition mainly concentrates on the UV band.