C掺杂AlN的电子结构和光学性质的第一性原理研究
First-principles study on the electronic structure and optical properties of C-doped AlN

采用基于密度泛函理论（DFT）的平面波超软赝势法，研究了C掺杂铅锌矿AlN的电子结构、磁性和光学性质。结果表明，C掺杂AlN产生了自旋极化，在带隙中引入杂质带形成受主能级，实现p型掺杂，同时表现出较强的半金属铁磁性，半金属能隙为0.315eV，理论上可实现100%的自旋载流子注入。掺杂后体系的介电函数虚部和光吸收系数在低能区出现新的峰值，吸收边向低能方向延展，能量损失明显减少。
Using the ultrapseudopotential method of plane wave based on density functional theory (DFT), the electronic structures，magnetic and optical properties were calculated and discussed in detail. It shows that C doped AlN produces spin polarization, which introduces impurity bands to form acceptor energy level in the energy gap and realizes p-type doping. The system shows strong half-metallic ferromagnetism and its half-metallic energy gap is 0.315eV, suggesting a polarization of the conduction carriers. The imaginary part of dielectric function and optical absorption function of the doping system show a new peak in low energy region. The absorption edge extends to low energy and energy loss decreases obviously.