第一性原理计算Cu-Cr共掺AlN稀磁半导体

First-principles Calculation of Cu-Cr Co-doped Al N Diluted Magnetic Semiconductors

采用基于密度泛函理论的第一性原理平面波超软赝势方法,结合广义梯度(GGA)近似对Cr单掺Al N和Cu-Cr共掺Al N的32原子超原胞体系进行几何结构优化,计算它们的晶格常数,能带结构,电子态密度以及光学性质.结果表明Cr单掺Al N和Cu-Cr共掺Al N均表现为半金属性质,带隙变窄,且Cu-Cr共掺体系自旋极化作用较Cr单掺强,材料表现出良好的铁磁性.共掺杂后,光吸收的范围增宽,体系对长波吸收加强,能量损失明显减小.

Geometrical structures of Cr doped and Cu-Cr co-doped 32-atoms supercell of AIN were optimized with first principles density functional based on full potential augumented plane waves and generalized gradient approximation （GGA）. Lattice constant, band structure, electronic density and optical properties were calculated. It indicates that Cr-doped and Cu-Cr co-doped AIN are both half metallic, their band gaps become narrower. Cu-Cr co-doped A1N system has stronger spin polarization effect than Cr doped, and exhibits fine ferromagnetic. Range of optical absorption becomes broader with doping. Co-doping enhances long-wave absorption and energy loss decreases obviously.