Mn掺杂GaN稀磁半导体的电磁特性研究

摘要

采用基于密度泛函理论的第一性原理平面波超软赝势法计算了不同浓度 Mn掺杂 GaN ( Ga1-x MnxN, x=0.0625和0.1250)的晶格常数、能带结构和态密度,分析比较了掺杂前后GaN的电子结构和磁性.结果表明：Mn掺入后体系仍为直接带隙半导体,带隙宽度随Mn含量的增加逐步增大. Mn掺杂GaN均使得N 2p与Mn 3d轨道杂化,产生自旋极化杂质带,自旋向上的能带占据费米面,掺杂后的Ga1-xMnxN表现为半金属铁磁性,适合自旋注入；随着Mn掺杂浓度的增加,体系的半金属性有所增强.%The lattice constant, band structures and density of states(DOS) of Mn doped GaN(Ga1-xMnxN, x=0. 0625 and 0. 125 ) was calculated by using first principles plane-wave ultra -soft pseudopotential method. The electronic structures and magnetic properties of GaN before and after Mn doped were studied. The results in-dicate that the system remains direct band gap semiconductor. The band gap becomes wider gradually with the increase of Mn content. Mn doped GaN makes N 2p and Mn 3d orbital hybridization and produces spin-polar-ized impurity band, the Fermi level goes into the spin-up energy band. Ga1-xMnxN doped by Mn shows half metallic ferromagnetism and is suitable for spin injection. Half metallic properties improve with the increasing concentrations of Mn doped.