Mg,O共掺杂实现p型AlN的第一性原理研究

采用密度泛函理论下的第一性原理平面波超软赝势方法研究了纤锌矿本征AlN,Mg单掺杂AlN和Mg,O共掺杂AlN体系的晶格参数、能带结构、电子态密度、差分电荷密度及电子布居数.计算结果显示:在Mg,O共掺杂AlN体系中,激活施主O原子的引入能使受主能级降低,形成浅受主掺杂.同时,体系的非局域化特征显著,受主能带变宽.因而提高了Mg原子的受主掺杂浓度和系统的稳定性.Mg,O共掺杂更有利于制备p型AlN.

First-principles study of Mg,O codoped p-type AlN

The lattice parameters, band structures, electronic densities of states and the charge densities of pure, Mg doped and Mg, O codoped wurtzite AlN are calculated by using the first-principles ultrasoft pseudo-potential approach of the plane wave based on the density functional theory. Calculations indicate that the introduction of activated donor O atoms causes the acceptor energy level to shift toward the lower energy level in the Mg, O codoped AlN, where shallow acceptors are formed. Meanwhile, the nonlocal characteristics and acceptor energy band widening become distinctive, thereby increasing the stability of the system and the doping concentration of Mg atoms. Mg, O codoping is more conducive to the preparation of p-type AlN.