凝聚相有机分子的激发能传递研究(Ⅱ)——激光染料二甲基-POPOP和DCM分子间的激发能传递

利用荧光发射及其衰变动力学测量,研究了激光染料分子二甲基-POPOP和DCM在溶液中的分子间能量传递。所得结果证实:激发态二甲基-POPOP分子荧光被猝灭的程度,随所加入DCM浓度的增大而增大。尽管DCM的荧光寿命随二甲基-POPOP的猝灭而增加。然而,DCM的加入并不改变二甲基-POPOP的荧光寿命。在固定DCM浓度,而增加二甲基-POPOP浓度时,相似的结果同样被观测到。这些结果表明:激发态二甲基-POPOP分子通过辐射传能机理向基态DCM传递激发能,其结果将入射光的波长从紫外直接转换到波长大于600nm的光谱区。在本文中也简要讨论了进一步改善这一传能过程效率的措施。

STUDY ON EXCITATION TRANSFER BETWEEN ORGANIC MOLECULES IN CONDENSED PHASE (Ⅱ):EXCITATION TRANSFER BETWEEN LASER DYE DIMETHYL-POPOP AND DCM MOLECULES

The excitation energy transfer between molcculars of laser dye dimethyl-POPOP and DCM in solution has been studied by measuring the fluorescence emission and decay kinetics. The results obtained show that the fluorescence of photoexcited dimethyl-POPOP was quenched by added DCM with the increase of the concentration of DCM. Though the fluorescence lifetime of DCM increased with the increase in dimethyl-POPOP''s fluorescence quenching adding DCM did not change the fluorescence lifetime of dimethyl-POPOP anyway. The similar effect was also observed in the case of increasing the concentration of dimethyl-POPOP, when the DCM in solution was kept at constant concentration. These results convincingly indicate that there is an excitation transfer from photoexcited dimethyl-POPOP to DCM via radiative transfer mechanism. As a consequence the wavelength of incident radiation can be converted directly from UV into spectral region above 600nm. In addition, the possible approac-es to improve the efficiency of this process are discussed in brief.