Dispersive electronic energy transfer in an organically doped xerogel glass Original Research Article

Time-resolved fluorescence depolarization measurements have been used to probe the wavelength dependence of optical energy transfer between quinizarin-aluminum chromophores in an aluminosilicate sol-gel glass. The optical energy transfer rate at low temperature is found to depend on the optical excitation energy due to inhomogeneous broadening of the absorption band. In contrast, energy transfer at room temperature is found to be nearly dispersionless, indicating significant vibronic contributions to the homogenous absorption line shape at higher temperatures. The dispersive energy transfer observed at low temperatures is analyzed using an energy trap model.