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采用第一性原理计算了Mn掺杂GaN非极性(100)薄膜的原子和电子结构.结果表明弛豫后表层Ga原子向体内移动,与Ga原子成键的表层N原子向体外移动,表层Ga-N键长收缩并扭转.通过对Mn原子掺杂在不同层总能量的比较,发现GaN(100)薄膜中Mn原子更容易在表层掺杂.弛豫后,掺杂在表层的Mn原子及与Mn原子成键的表层N原子都向体内发生很小的移动,Mn-N键没有发生明显扭转,但是弛豫后N原子向Mn原子靠近,Mn-N键收缩.Mn原子的掺杂使得Mn3d与N2p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.掺杂后的薄膜表现为半金属性,适合于自旋注入.
The atomic and electronic structures of the Mn-doped GaN nonpolar (100) thin films were calculated using first-principles calculations. The results show that the Ga atoms move toward the body after relaxation, and the surface N atoms that bond with the Ga atoms move in vitro , The surface Ga-N bond shrinks and twists.Comparing the total energy of Mn atoms doped in different layers, it is found that the Mn atoms in GaN (100) thin films are more easily doped in the surface layer.After relaxation, The Mn atoms in the surface layer and the surface N atoms in the surface bond with Mn atoms all migrated little to the inside of the body, and the Mn-N bond did not turn around obviously. However, after the relaxation, the N atom was closer to the Mn atom and the Mn- The doping of atoms makes the hybridization of Mn3d and N2p orbitals, resulting in spin-polarized impurity bands with spin-up energy bands occupying the Fermi surface.The doping films are semimetallic and are suitable for spin injection.