In掺杂ZnO电子结构的第一性原理研究

采用第一性原理平面波超软赝势,计算了纤锌矿ZnO和不同掺杂量下In掺杂ZnO晶体的能带结构、态密度和分波态密度.计算表明,In的掺杂导致ZnO禁带宽度变窄.随着掺杂量的增大,In_xZn_1－xO的导带底和价带顶同时下降,但是导带底比价带顶下降得多,这导致了带隙的变窄.此外,In掺杂使晶胞晶格常数增大,这对带隙的变窄也有一定作用.

First-principles study on electronic structure of In-doped wurtzite ZnO

The band structure, total density of states and partial density of states of pure and In-doped wurtzite ZnO have been investigated by using the first-principles ultrasoft pseudo potential approach of the plane wave. The calculation indicates that the band gap of ZnO is reduced by In doping. The energies of both the conduction band minimum and the valence band maximum decrease with increasing In-doping concentration, but the decrease of the conduction band minimum is much more pronounced than that of the valence band maximum, which leads to narrowing of the band gap. Moreover, it was found that In-doping can cause increase of the lattice constant, which also reduces the band gap.