摘要
利用基于密度泛函理论的第一性原理对In掺入ZnTe半导体后引入的各种缺陷进行了结构优化、能带和态密度分析及转换能级的计算.计算结果表明:掺杂后体系中主要存在两种缺陷,一种是In原子替换了Zn原子的置换型缺陷;另一种是由In替换Zn后再与临近的Zn空位形成的复合缺陷.二者分别在导带底下方0.26eV和价带顶上方0.33eV的位置形成各自的转换能级.电子在这两个转换能级之间跃迁辐射出的能量大小与实验测量到的能量大小相符,解释了原本发绿光的ZnTe在掺入In后发出近红外光的根本原因.
First-principles theory is adopted to analyze the characteristics of defects in ZnTe induced by In doping.The geometry structures,formation energies,band structures,densities of states and transition levels of the defects are calculated.The results show that there are two kinds of major defects in In-doped ZnTe.One is the atomic substitution defect of Zn replaced by In,which gives rise to a transition level located at 2.6 eV beneath the conduction band.The other is a complex defect,consisting of one In substituting Zn and one nearby Zn vacancy,which results in a transition level 0.33 eV higher than the top level of valance band.Electron transition between these two transition levels can be regards as the origin of the near-infrared light observed experimentally in In-doped ZnTe.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第10期89-95,共7页
Acta Physica Sinica
