碲镉汞材料中Hg空位缺陷的第一性原理研究

利用基于第一性原理的全电子势线性缀加平面波方法计算了在碲镉汞材料中Hg空位所引起的晶格弛豫以及空位对周围原子成键机制的影响.通过成键过程中电荷密度的变化以及电荷转移的讨论，论述了碲镉汞材料Hg空位引起的弛豫以及这种弛豫产生的主要原因.通过态密度的计算和分析，发现Hg空位的形成将导致第一近邻阴离子Te的5s态能量向高能端移动了055eV，并借助Te 5s态电荷密度与成键电荷密度的计算结果，分析了引起该能态能量平移的主要原因.通过带边态密度变化以及Kohn-Sham(KS)单电子能级的计算和分析，得出了Hg 关键词： 碲镉汞 Hg空位 线性缀加平面波方法

First-principles calculations on the mercury vacancy in Hg0.5 Cd0.5 Te

Using the density-functional theory within the full-potential linear augmented plane wave method, we have calculated the influence of the mercury vacancy on the bonding mechanism and the relaxation effects in the Hg 0.5 Cd 0.5 Te (MCT) alloy. The bonding charge density and charge transfer gave the explanation for the relaxation results. The results of density of states revealed that the re-coupling of the dangling bond of the nearest neighbor (NN) of the vacancy make the NN Te 5s state energy level shift up. The reasons for the energy level shift were discussed with the Te s-state bonding charge density. The results of the partial density of state at the band edge reveal that the mercury vacancy will narrow the band gap of the MCT materials.