Mg掺杂ZnO所致的禁带宽度增大现象研究

Investigation on the broadening of band gap of wurtzite ZnO by Mg-doping

采用第一性原理的超软赝势方法,研究了纤锌矿ZnO及不同量Mg掺杂ZnO合金的电子结构.理论计算表明,Mg的掺杂导致ZnO晶体的禁带宽度增大.研究发现,Zn4s态决定导带底的位置,Mg的掺入导致Zn4s态向高能端的偏移是导致禁带宽度增大的根本原因.

The electronic structure of pure and Mg-doped wurtzite ZnO has been investigated by using first-principles ultrasoft pseudopotential method in the generalized gradient approximation. The calculation indicates that the band gap of ZnO broadens with increasing Mg-doping concentrations. Our work shows that the bottom of conduction band is determined by the Zn 4s electron states which can shift to a higher energy due to Mg-doping.