SiN分子外电场情况下的发光特性

为全面分析外电场对分子发光特性的影响, 本文采用密度泛函B3P86方法6-31g(d)基组, 对SiN分子进行了基态结构的优化, 进而使用含时密度泛函方法(time dependent density functional theory, TDDFT), 计算了不同方向及大小的外电场情况下SiN分子的吸收谱、激发能、振子强度、跃迁偶极矩. 通过比较发现外电场对该分子的激发能、吸收谱、跃迁振子强度及跃迁偶极矩影响都比较明显, 说明了电场对SiN分子的激发特性影响比较复杂, 特别是在加场前后分子均有在可见光区波段的吸收谱, 这对研究分子的发光很有意义.同时对该分子所发可见光谱的产生机理进行了分析, 并与已有实验结果进行比较.

Electroluminescence properties of SiN molecule under different external electric fields

In order to find how the external electric field affects the SiN molecule completely, in the present work the density functional B3P86/6-31(g) method is adopted to optimize the ground state structure and the time dependent density functional theory TDDFT/6-31(g) is used to study the absorption spectra, emission spectra, excited energies, oscillator strengths and dipole moments of SiN molecule under different external electric fields. We find that the absorption spectrum, excited energy, oscillator strength and dipole moment of SiN molecule are affected strongly by external electric field. One of the valuable results is that the absorption spectra in violet light and blue wavelength ranges of SiN molecule each have a red shift. The luminescence mechanism of visible light for SiN molecule is also investigated and compared with the experimental data.