第一性原理计算研究立方氮化硼空位的电学和光学特性

对立方氮化硼的空位进行了基于密度泛函理论框架下的第一性原理平面波超软赝势方法的研究. 通过对总能量、能带结构、态密度及电子密度分布图的分析发现, B空位相比起N空位更加稳定. 并且空位仅影响最近邻原子的电子分布, 空位浓度的增加使禁带宽度逐渐变窄. 从复介电函数和光学吸收谱分析中发现, 随着空位浓度的增加, 立方氮化硼在深紫外区的吸收逐渐减弱. 并且B空位还导致在可见光区域出现明显的吸收带. 关键词： 立方氮化硼 空位 第一性原理 电光学特性

First-principle study of vacancy-induced cubic boron nitride electronic structure and optical propertiy changes

Influences of vacancies on the electronic and optical properties of cubic boron nitride were investigated by using first-principles ultra-soft pseudopotential approach of the plane wave, based on the density functional theory. It was found that the formation of B vacancy is stable from the view of energy. Only the nearest atom were affected by vacancy, and the bandgap decreased from 6.3 eV to 2.86 eV or to 3.43 eV, by the introduction of 4.17% B or N vacancy . In addition, the boron vacancy also induce the emergence of an absorption band in the visible region, with the increase in vacancy concentration, the absorption in the visible region increased gradually, while the absorption in the ultraviolet region decreased.