【摘要】 采用基于密度泛函理论的第一性原理全势线性缀加平面波法,研究了Li-O共掺杂纤锌矿AlN体系的晶格结构、电子态密度、能带结构和光学性质,较详细地分析了O对Li掺杂AlN晶体p型特性的影响。结果表明:Li-O共掺杂会导致AlN晶格收缩和禁带宽度减小;与Li单掺杂相比,O杂质的加入使得价带顶部的态密度峰值减小且局域化加强,降低了Li在AlN晶体中的受主特性。相较于未掺杂时的情况,Li-O共掺杂AlN的介电函数虚部谱只保留了位于7.5 eV处的主峰,谱线也变得更加平缓,而材料的吸收区范围未受到影响。Li-O共掺杂后的AlN材料依然能很好地工作在紫外光区域。更多还原

【Abstract】 Based on first-principles full-potential linearized augmented plane-wave method( FP-LAPW)density functional theory( DFT),the crystalline structure,the density of states,the band structure and the optical properties of p-type Li-O codoped wurtzite AlN were investigated theoretically. The calculation results show that both the lattice constants and the band gap of AlN crystal will shrink due to the Li and O impurities codoping; the density of states around maximum of the valence band has been reduced and its localization has got strengthened compared to the Li doping situation. Li-O codoping depressed the ptype properties of Li doped AlN. The calculated dielectric function reveals that all the other peaks vanish except the main peak located at 7. 5 eV after Li-O codoping and the spectrum becomes smooth,but the absorption region remains unchanged. The Li-O codoped AlN crystal still works excellently in the ultraviolet region.更多还原