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采用基于密度泛函理论(DFT)框架下广义梯度近似(GGA)的PBE平面波超软赝势方法,计算了本征ZnO,Al掺杂ZnO(ZnAlO)和Ga掺杂ZnO(ZnGaO)的能带结构、态密度、复介电函数和复电导率.其中Al或Ga是以替位杂质的形式进入ZnO晶格.计算结果表明纤锌矿型ZnO,ZnAlO和ZnGaO都是直接带隙半导体材料,掺杂后ZnO的带隙变小,且ZnAlO的带隙略大于ZnGaO.掺杂后ZnO)的电子结构发生变化,费米能级由本征态时位于价带顶上移进入导带,ZnO表现为n型掺杂半导体材料,掺杂后在导带底出现大量由掺杂原子贡献的自由载流子—电子,明显提高了电导率和介电函数,改善了ZnO的导电性能,并且ZnAlO的导电性能要略好于ZnGaO.
The energy bandgap of intrinsic ZnO, Al-doped ZnO (ZnAlO) and Ga-doped ZnO (ZnGaO) was calculated using the PBE plane wave super soft pseudopotential method based on the generalized gradient approximation (GGA) Structure, density of states, complex dielectric function and complex conductivity, in which Al or Ga enters the ZnO lattice as a substitute impurity.The results show that the wurtzite ZnO, ZnAlO and ZnGaO are all direct band gap semiconductor materials, After doping, the bandgap of ZnO becomes smaller and the bandgap of ZnAlO is slightly larger than that of ZnGaO.The electronic structure of ZnO changes after the doping, and the Fermi level shifts from the eigenstate to the conduction band at the top of the valence band. Is an n-type doped semiconductor material. After doping, a large amount of free carrier-electrons contributed by doping atoms appear at the bottom of the conduction band, which obviously improves conductivity and dielectric function and improves conductivity of ZnAlO Conductive properties should be slightly better than ZnGaO.