J型聚集态的激光光谱学实验与理论研究

Experimental and Theoretical Study of J-Aggregate State

观测到了光敏染料1,1’-乙二基—2,2’-甲川喹啉碘化物的吸收光谱随温度和浓度的变化关系,及其J-聚集态的离子增强效应,给出奇异J-谱带出现的温度的临界参数。最后利用超快速光谱学技术研究了J-聚集态的共振荧光动力学,确定其衰减时间小于20ps,并建立了一个亚宏观有序集体振动模相变的理论模型,解释了J-谱带波长位置,谱带的窄带性,以及共振荧光快速弛豫对聚集分子和外界条件不敏感的特性,同时还解释了J-谱带出现的临界行为及其对分子的选择。

The absorption spectra of the dye 1,1'-diethy1-2,2'-cyanine iodide(DCI) in the mixture solvent EGW at various temperature and dye concentrations are presented.The ion-reinforcing effect of KI on the J-aggregation of DCI is de- scribed.The relaxation of the J-aggregated excited state in the J-band is measured to have a decay time shorter than 20ps.A theoretical model for the molecular aggregation of sub-macroscopic order collective vibration mode is proposed to explain the J-band charateristics such as its peak position,unusual narrow bandwidth,ultrafast decay resonant fluorescence and its insensitivity to the external condition.The critical behavior and the molecule selectivity of the J-band occurrence are also explained.