浓度对Co掺杂ZnO的影响的第一性原理研究

Study of the cobalt concentration influence on Co-doped ZnO by first- principles calculation theory

采用基于密度泛函理论的第一性原理平面波超软赝式方法,详细研究了本征Zn O和Co掺杂Zn O的电子结构和光学性质.计算结果表明,Co掺入Zn O后,Co的大部分3d电子位于费米能级附近,O的2p轨道电子发生分裂,并进入费米能级与Co的3d电子发生杂化,价带电子向低能级端移动,带隙变大,但随掺杂浓度的增大这种现象并不明显.另外Zn O掺Co后,由于Co的3d电子的引入,使得吸收谱中出现新的吸收峰,并发生蓝移现象,这与实验得到的结果相一致;静态介电常数明显增大,但随掺杂浓度的增大基本保持不变.

The electronic structure and optical properties of pure and Co-doped ZnO have been calculated from the first-principles of plane wave ultrasoft pseudopotential method base on density functional theoty.The results show that most of the 3d electron of Co is located near the Fermi level and Oxygen’s 2p orbital electrons split at Fermi energy level and apparent interaction between the O 2p and Co 3d, which leads to the valence band elec-tronic shifts to lower energy and the band gap becomes larger, but the change is not obvious with the increase of the doping concentration.;On the other hand, certain changes of the optical properties of Co-doped ZnO take place , i.e., a new absorption peak happens in ZnO absorption spectrum and blue shift is apparent which is con-sistent with the experimental results;and the stastics dielectric function larger than pure ZnO, but with the in-crease of the doping concentration, there is no obvious change.