Hg掺杂CdTe所致禁带宽度变窄的理论研究

采用基于密度泛函理论的第一性原理平面波超软赝势方法，研究了闪锌矿CdTe及不同量Hg掺杂HgxCd1-xTe的电子结构，给出了相应的的能带结构、态密度、差分电荷分布及光吸收谱。计算结果表明，随着Hg掺杂含量的增加，体系禁带宽度逐渐变窄，并给出了禁带宽度变窄的微观机理。

Theoretical investigation on the narrowing of band gap of sphalerite CdTe by Hg-doping

The electron properties of pure and Hg-doped sphalerite phase CdTe crystal have been calculated by first-principle ultra-soft pseudo-potential approach of the plane wave based upon the density functional theory, the calculation of energy band structure, density of states, difference charge density and absorption spectra of HgxCd1-xTe were carried out. The calculated results give the reason why the band gap becomes gradually narrow with the increasing of the Hg content.