用第一性原理研究Sn掺杂 Ga1.375In0.625O3的电子结构和导电性

用第一性原理计算了Sn 替位Ga1.375In0.625O3化合物的Ga 原子(Ga1.25In0.625Sn0.125O3)和Sn 替位Ga1.375In0.625O3化合物的In原子(Ga1.375In0.5Sn0.125O3)的结构、电子能带和态密度。Ga1.25In0.625Sn0.125O3半导体材料比Ga1.375In0.5Sn0.125O3材料具有大的晶格参数和强的Sn–O离子键。在Sn掺杂 Ga1.375In0.625O3化合物中,Sn 原子优先取代In 原子。Sn掺杂 Ga1.375In0.625O3化合物显示n型导电性, 杂质能带主要由Sn 5s 态组成。Ga1.375In0.5Sn0.125O3化合物的光学带隙大于Ga1.25In0.625Sn0.125O3化合物的光学带隙。 Ga1.25In0.625Sn0.125O3 具有小的电子有效质量和大的电子迁移率,Ga1.375In0.5Sn0.125O3 具有多的相对电子数和好的导电性。

First-principles study on electronic structure and conductivity of Sn-doped Ga1.375In0.625O3

The structural properties, band structures and densities of states of Sn-doped Ga_1.375In_0.625O₃ with a Sn atom substituting for the Ga atom or a Sn atom substituting for the In atom are calculated by using the first-principles method. The substitution of the Sn atom for the Ga atom in Ga_1.375In_0.625O₃ (Ga_1.25In_0.625Sn_0.125O₃) has larger lattice parameters and stronger Sn-O ionic bonds than that of the substitutional doping of the Sn atom for the In atom in Ga_1.375In_0.625O₃ (Ga_1.375In_0.5Sn_0.125O₃). Results show that the Sn atom is preferentially substituted for the In atom in Sn-doped Ga_1.375In_0.625O₃. Sn-doped Ga_1.375In_0.625O₃ exhibits n-type metallic conductivity, and the impurity bands are mainly provided by the Sn 5s states. The optical band gap of Ga_1.375In_0.5Sn_0.125O₃ is larger than that of Ga_1.25In_0.625Sn_0.125O₃. Ga_1.25In_0.625Sn_0.125O₃ has a smaller electron effective mass and a slightly larger mobility. However, Ga_1.375In_0.5Sn_0.125O₃ has a larger relative electron number and a slightly higher conductivity.