ZnO在辐射场中的光激发特性研究

采用密度泛函理论的BPV86方法, 在6-311G++(d, p)基组水平上优化了不同外电场(0～0.080 a.u.)下氧化锌分子的基态稳定构型, 在此基础上利用同样的方法计算了氧化锌分子的分子结构、偶极矩、总能量、能隙以及红外光谱和紫外-可见吸收光谱强度。结果表明, 在外电场的作用下, 分子结构变化明显, 与电场呈现强烈的依赖关系。随着正向外加电场的增加, ZnO分子键长一直在增大, 电偶极距也是一直增大, 分子总能量不断减小, 分子能隙不断减小, 红外光谱吸收峰出现红移现象。随着外电场的加强, 分子紫外可见吸收光谱振子强度先增大后减小再增大再减小反复变化, 其波峰则出现蓝移现象。

Optical Excitation Characteristics of ZnO under the Radiation Fields

Based on the density functional theory DFT/BVP86 at 6-311++g(d,p) level, the ground states of ZnO molecule under different external electric fields are optimized. The influence of external electric field ranges from 0 to 0.08 a.u. on the geometrical parameters, dipole moment, total energy, energy gap., Infrared spectrum and UV-VIS absorption spectrum intensity are studied. The results show that the change of molecular structure is obvious, and it becomes strongly dependent on the field strength. As the electric field changes from 0 to 0.08 a.u., the bond length of ZnO molecular increases. And the electric dipole moment is proved to be increasing and the total molecular energy is decreasing all the time. The energy gap of E_G is found to decrease with the increasing external field. The IR vibration spectrum of ZnO molecule shows an observable red shift. The oscillator strength of UV-Vis absorption spectrum is proved to be repeating the changes of the first increasing and then decreasing. The ultraviolet absorption peak is blue-shifted with the increase of the field intensity.