C与Na掺杂AlN电子结构与光学性质的第一性原理研究

基于密度泛函理论(DFT)的平面波超软赝势法，计算了本征AlN,C-AlN,Na-AlN以及C-Na-AlN四种体系的电子结构和光学性质.得出结论：掺杂后各体系与本征AlN相比发生了晶格畸变，C-Na-AlN体系的结合能最小，体系最稳定.掺杂体系相比于本征AlN,禁带宽度都有不同程度的减小，导致电子在体系内跃迁时的概率增大，其中C-Na-AlN体系尤为明显，电子跃迁所需要的能量更小.掺杂后吸收带边发生了红移，拓宽了AlN体系对光的响应范围，增强了光吸收，并且C-Na-AlN体系在可见光区域内光吸收能力最强，在介电函数图的分析中可以得到，C-Na-AlN体系的介电常数最大，表明其电荷束缚能力最强，体系稳定性强，极化能力最好.

First principles study on electronic structure and optical properties of C and Na doped AlN

Based on the plane wave ultra soft pseudopotential method of density functional theory (DFT), the electronic structures and optical properties of intrinsic AlN, c-aln, Na AlN and c-na-aln were calculated. It is concluded that after doping, lattice distortion occurs in each system compared with intrinsic AlN, and the binding energy of c-na-aln system is the smallest and the system is the most stable. Compared with the intrinsic AlN, the band gap width of the doped system decreases to varying degrees, resulting in an increase in the probability of electron transition in the system, especially in the c-na-aln system, which requires less energy for electron transition. After doping, the absorption band edge has a red shift, which widens the response range of AlN system to light and enhances the light absorption. Moreover, c-na-aln system has the strongest light absorption ability in the visible light region. From the analysis of dielectric function diagram, it can be seen that c-na-aln system has the largest dielectric constant, which shows that its charge binding ability is the strongest, the stability of the system is strong, and the polarization ability is the best.