高能Zn离子注入CaF2基质形成ZnO纳米粒子的机制、构型及电子结构

将高能Zn2+注入到CaF2介电基质中,在CaF2的表面下注入Zn2+浓度呈近似高斯分布,通过氧气氛后经热退火形成ZnO量子点.采用MaterialsStudio和Gaussian98W程序,结合实验结果计算分析了CaF2基质中ZnO纳米粒子的电子结构和光学性质.选取由4个ZnO原胞组成的超晶胞模型计算了ZnO纳米粒子的吸收光谱,理论结果与实验结果相符.对ZnO纳米粒子电子结构的研究结果表明,ZnO纳米粒子与CaF2基质的相互作用主要是ZnO表面的O与基质中Ca之间的作用,这种作用使ZnO纳米晶体的Fermi能级变窄,带隙相应减小;ZnO纳米粒子表面构型的变化对其本征吸收光谱没有影响,理论计算结果与实验值一致.

Mechanism, Configuration and Electronic Structure of ZnO Nanoparticles Formed by Zn Ions Implantation into CaF2 Matrix

By implantating high energy Zn ion into CaF2 matrix,the concentration of the implanted ions has a Gaussian's distribution below the surface of the CaF2,and ZnO quantum dots can be obtained by thermal annealing. Based on the theory of quantum chemistry,using Materials Studio and Gaussian 98 W programs,the electronic structure and optical properties of ZnO nanoparticles on GaF2 matrix were analysized.(Selecting) four of super-cells from the basal cells of ZnO,the Absorption spectra of ZnO were calculated,and the result corresponds to the experimental one.The investigation of electionic structure of ZnO shows that the interaction of ZnO with GaF2 matrix is mainly from the interaction of O atom on ZnO surface with Ca,this interaction leads to the narrow of Fermi energy level and decrease of energy gap.The change of the structure of ZnO surface did not affect the diagnostic Absorption spectra,the theoretical results are the same as the experimental ones.