Si(CH_3)_4的MPD与Si原子的双光子共振三光子电离

Multiphoton dissociation of tetramethylsilane and two photon resonance three photon ionization of silicon atoms

在 410～ 40 4nm的紫激光作用下 ,利用平行板电极装置研究了Si(CH3) 4的多光子解离 (MPD)及Si原子的双光子共振三光子电离。观察到了Si(CH3) 4分子经MPD产生的、处于 33PJ″(J″ =0 ,1,2 )态的硅原子 ,依据 43PJ′← 33PJ″(J′、J″=0 ,1,2 )跃迁谱线的强度 ,得到了Si(CH3) 4经MPD产生的、处于 33PJ″(J″=0 ,1,2 )态的硅原子的密度分布值 ,并进行了理论计算 ,依据双光子跃迁的选择定则及其附加定则 ,对 410～ 40 4nm内的跃迁谱峰作了归属。根据这些结果 ,讨论了Si(CH3) 4的MPI机理 ,得到了在这一波段内 ,于本文的实验条件下 ,Si(CH3) 4的MPI机理主要为B类光化学行为的结论。

Multiphoton dissociation (MPD) of tetramethylsilane and two photon resonance three photon ionization of silicon atoms are studied with parallel plate vacuum cell at violet laser radiation in the wavelength range 410～404nm.The silicon(3→｜ 3P″ J) J″ (J″=0,1,2)atoms produced due to MPD of tetramethylsilane are observed.According to the line intensities for the 4→｜ 3P J′ ←3→｜ 3P J″ (PJ″=0,1,2) transitions,the population distributions of the Si(3 3P J″ )(J″=0,1,2)states produced due to MPD of tetramethylsilane are determined and calculated theorically.According to the selection rules and its additional selection rules for two photon dipole transitions in atoms,transitions in the wavelength range 410～404nm are labelled.According to these results,multiphoton ionization(MPI) mechanism of teiramethylsilane is discussed.The conclusion is drawn that the tetramethylsilane are mainly class B photochemical behavior in the wavelength range 410～404nm.