摘要
运用密度泛函理论体系下的平面波赝势(PWP)和广义梯度近似(GGA)方法,计算研究了闪锌矿结构的ZnS晶体在不同的外界压强下的电子结构.通过分析发现,随着外界压强的增大,晶格常数和键长在不断缩小,从S原子向Zn原子转移的电荷越来越少,Zn—S键的共价性逐渐增强,Zn原子和S原子的态密度都有不同程度的变化,而且还有向低能量移动的趋势.当外界压强达到24GPA时,ZnS从直接带隙半导体变成间接带隙半导体,而且随着压强的增大,间接带隙逐渐变小,直接带隙逐渐增大.
We have calculated the electronic structure of zinc blende structure ZnS under different high pressures by means of plane wave pseudo-potential method（PWP） with generalized gradient approximation （GGA） in this paper. We have found that the lattice constants and bond length decrease with pressure increasing. The charge transfer from S atoms to Zn atoms becomes less, and the covalence nature of Zn-S bond becomes stronger. Secondly, the peak of density of states of Zn atoms and S atoms change to some degree. Furthermore, it has a shifting tendency towards lower energy. On the other hand, ZnS turns from direct band gap to indirect band gap semiconductor when ambient pressure reaches 24 GPa. The indirect band gap narrows and the direct band gap widens with pressure increasing.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第7期4079-4084,共6页
Acta Physica Sinica
基金
江苏省高校自然科学研究项目资助的课题.~~
关键词
闪锌矿结构
态密度
能带结构
密度泛函理论
zinc blende structure, density of states, energy band structure, density function theory
