Ga掺杂对纤锌矿TM0.125Zn0.875O(TM=Be,Mg)电子结构和光学能隙的影响

Effect on the electronic structures and optical bandgaps of Ga-doped wurtzite TM_(0.125)Zn_(0.875)O (TM=Be,Mg)

利用密度泛函理论的平面波超软赝势方法,对纤锌矿T M_(0.125)Zn_(0.875)O(TM=Be,Mg)合金和Ga掺杂T M_(0.125)Zn_(0.875)O的结构参数、能带、电子态密度和光学能隙进行计算和分析,结果表明:T M_(0.125)Zn_(0.875)O掺入Ga容易实现并且结构更稳定,T M_(0.125)Zn_(0.875)O合金掺Ga能获得很好的n型材料改性,能隙由导带底Ga 4s态和价带顶O 2p态决定,由于Bllrstein-Moss移动和多体效应,Ga掺杂后的T M_(0.125)Zn_(0.875)O光学能隙变大,这与实验结果相一致,T M_(0.125)Zn_(0.875)O掺Ga材料可作透明导电薄膜应用到紫外和深紫外光电子器件中。

The optimized structure parameters, electron density of states, energy band structures and optical bandgaps of the T M0.125Zn0.875O （T M =Be, Mg） alloys and Ga-doped T M0.125Zn0.875O are calculated and analyzed by using the ultra-soft pseudopotential approach of the plane-wave based upon density functional theory. The theoretical results show the Ga-doped T M0.125Zn0.875O materials are easily obtained and their structures are more stable. The Ga-doped T M0.125Zn0.875O are good n-type materials and their energy bandgaps are determined by Ga 4s states of the conduction band minimum and O 2p states of the valence band maximum. Compared with the T M0.125Zn0.875O alloys, the optical bandgaps of Ga-doped T M0.125Zn0.875O become wider due to the Burstein-Moss shift and many-body effects, which is consistent with previous experimental data. The Ga-doped T M0.125Zn0.875O materials are suitable as TCO films for the UV and deep UV optoelectronic device.