Influence of point defects on optoelectronic properties of Al0.375Ga0.625N
Influence of point defects on optoelectronic properties of Al0.375Ga0.625N
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点缺陷对Al0.375Ga0.625N光电性能的影响
DOI：
10.1016/j.ijleo.2017.11.065
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发表时间：
2018
期刊：
影响因子：
3.1
通讯作者：
Rao Weifeng
中科院分区：
文献类型：
--
作者：
Yang Mingzhu;Fu Xiaoqian;Wang Xiaohui;Guo Jing;Rao Weifeng
为了研究本征点缺陷对Al0.375Ga0.625N电子结构和光学性质的影响，建立了Ga、Al和N空位对应的Al0.375Ga0.625N、Al0.375Ga0.5625N、Al0.3125Ga0.625N和Al0.375Ga0.625N0.9375模型。基于第一性原理计算，得到了点缺陷晶体的形成能、原子结构、能带结构、态密度、Mulliken电荷布居和光学性质，结果表明：Ga空位的Al0.375Ga0.5625N晶体和Al空位的Al0.3125Ga0.625N晶体具有p型性质，同时，具有N空位Al 0.375Ga 0.625N 0.9375晶体表现出典型的晶体结构。Al0.375Ga0.5625N和Al0.3125Ga0.625N的费米能级进入价带，而Al0.375Ga0.625N0.9375的费米能级进入导带。N空位的形成能最低，说明N空位最容易存在。缺陷晶体的整体转移指数均低于纯晶体。由于较短的键，缺陷周围的键数增加。对于缺陷晶体，在低能区出现了新的反常色散区，在0-2 eV范围内，缺陷晶体的反射率比纯晶体的反射率高。
In order to study the influence of native point defects on the electronic structure and optical properties of Al0.375Ga0.625N, models of Al0.375Ga0.625N, Al0.375Ga0.5625N, Al0.3125Ga0.625N, and Al0.375Ga0.625N0.9375which correspond to Ga, Al, and N vacancies were built. Based on first-principles calculation, formation energies, atomic structures, band structures, density of states, Mulliken charge populations, and optical properties of the crystals with point defects were obtained.Results show that the Al0.375Ga0.5625N crystal with Ga vacancy and the Al0.3125Ga0.625N crystal with Al vacancy showp-type property, meanwhile, the Al0.375Ga0.625N0.9375crystal with N vacancy shown-type property. The Fermi level of Al0.375Ga0.5625N and Al0.3125Ga0.625N enter into valence band while the Fermi level of Al0.375Ga0.625N0.9375enters into conduction band. The formation energy of N vacancy is the lowest, showing it is the easiest for N vacancy to exist. The global transfer index values of the defective crystals are all lower than that of the pure one. The bond populations around the defects increase because of the shorter bonds. For the defective crystals, there appear new abnormal dispersion ranges at the low energy region, and the reflectivities of the defective crystals are higher than that of the pure one at the range of 0–2 eV.