We show that the method we have developed for measuring the singlet exciton diffusion length in blends with [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) can be applied not only to polymeric materials, but also to small molecule organic semiconductors. Small organic molecules have a large potential for molecular re-organization upon thermal annealing. Here we show that the exciton diffusi...

Numerical simulations of exciton migration along a one-dimensional lattice via Forster energy transfer are reported. The roles of static Gaussian energetic disorder and transition dipole orientational disorder are investigated. Both disorder mechanisms result in subdiffusive behavior during the initial phase of energy migration, tending asymptotically to normal diffusion. The dependence of the ...

Fluorescence and phosphorescence phonon sidebands of isotopic mixed hexamethylbenzene crystals at 2°K are presented. The external phonons can be observed separately from the semi-internal (methyl torsion) ones. The nature of the electronic or vibronic state has observable but not drastic effects on the exciton-phonon coupling function. Likewise, the exciton delocalization is of minor importance...

Femtosecond two-pulse degenerate four-wave mixing spectroscopy was applied to study the exciton dephasing in a broad range of excitation intensities and lattice temperatures. We find that both exciton-exciton and exciton-phonon scattering have profound effects on the dephasing process. The dominant phonon mode involved in the dephasing is identified as the out-of-plane, transverse optical mode ...

We have observed that photoemission from single-walled carbon nanotubes saturates in intensity as the excitation intensity increases. Each emission peak arising from specific-chirality tubes exhibited a saturation value independent of the excitation wavelength, suggesting an upper limit on the exciton density for each nanotube species. We developed a model based on diffusion-limited exciton-exc...

We address the lattice deformation of 1T-TiSe2 within the exciton condensate phase. We show that, at low temperature, condensed excitons influence the lattice through electron-phonon interaction. It is found that at zero temperature, in the exciton condensate phase of 1T-TiSe2, this exciton condensate exerts a force on the lattice generating ionic displacements comparable in amplitude to what i...

In this study, the two-photon excited fluorescence spectra from cadmium selenide quantum dots (QDs) on a silicon nitride photonic crystal (PhC) membrane under femtosecond laser irradiation were investigated. These spectra can be fit to a tri-Gaussian function in which one component is negative in amplitude, and in which the Gaussian components with positive amplitude are assigned to exciton emi...

Surface plasmon (SP) coupling has been successfully applied to nonradiative energy transfer via exciton-plasmon-exciton coupling in conventionally sandwiched donor-metal film-acceptor configurations. However, these structures lack the desired efficiency and suffer poor photoemission due to the high energy loss. Here, we show that the cascaded exciton-plasmon-plasmon-exciton coupling in stratifi...

We investigate exciton emission of quantum well embedded in a semiconductor microcavity. The analytical expressions of the light intensity for the cases of excitonic number state and coherent state are presented by using secular approximation. Our results show that the effective exciton-exciton interaction leads to the appearance of collapse and revival of the light intensity. The revival time ...

The optical functionalities such as exciton recurrence and migration for dendritic systems, e.g., dendrimers, are investigated using the quantum master equation (QME) approach based on the ab initio molecular orbital configuration interaction (MOCI) method, which can treat both the coherent and incoherent exciton dynamics at the first principle level. Two types of phenylacetylene dendrimers, Ca...