Be掺杂浓度对ZnBeO体系电子结构的影响

采用基于密度泛函理论的第一原理方法,计算了Zn16-nBenO16掺杂体系所有的652种不同几何构型.结果表明：掺入ZnO的Be原子均匀分散,不出现聚集,与实验中没有观测到ZnO和BeO出现相分离这一现象吻合;掺杂浓度为25%、50%和75%时,掺杂的Be原子均匀对称地分布在32个原子组成的超原胞中,此时体系处于最稳状态;优化Be浓度从0到100%的掺杂体系几何结构,获得的晶格参数与实验值吻合较好,符合Vegard’Law拟合带隙曲线,得到的禁带弯曲系数b为5.76eV.

The Effect of Be-composition on the ZnBeO Electronic Structure

Using first principle calculation based on density functional theory（DFT）,the 652 different structures of the Zn16-nBenO16 system are investigated.The results indicate that：the doped Be atoms in ZnO are homo-dispersed,don’t appear together.This coincides well with the experiment that one can’t find the phase separation between the ZnO and BeO.When doping density are 25%,50% and 75%,the doped Be atoms are distributed symmetrically in the 32-atom supercell,and the doping systems are in most steady state.As the Be composition varys from 0to 100%,the calculated lattice parameters of the optimized doping structures are in good agreement with the experiments,and obey the Vegard ’s Law well.Fitting the bandgap,the bowing coefficient bis about 5.76eV.