采用Frenkel激子理论研究了一维线性和二维人字形分子聚集体的吸收和发射光谱.通过引入激子离域长度的概念,将聚集体与单分子的光谱线形函数联系起来.计算的光谱结果表明,聚集体的光谱与分子在聚集体中的排列紧密相关.分析了一维J聚集光谱发生红移以及二维人字形分子聚集体吸收光谱形成J和H激子谱带的内在原因.模拟得到的聚集体的吸收和发射光谱与实验结果一致.
The absorption and emission spectra of one-dimensional linear aggregates and two-dimensional herringbone aggregates were investigated via Frenkel exciton model.The introduction of the exciton delocalization length bridges a link between spectral lineshape fuctions of molecular aggregates and single molecule.The results show that the spectra of molecular aggregates are closely dependent on the molecular alignment.The red-shift absorption in linear J aggregates and splitting of J and H bands in herringbone aggregates are analyzed.The simulated absorption and emission spectra are in consistent with experimental results.