Many-body levels of optically excited and multiply charged InAs nanocrystals are studied with the semiempirical tight-binding model. Single-particle levels of unstrained spherical InAs nanocrystals are described by the spds* nearest-neighbor tight-binding model including spin-orbit coupling. For optically excited InAs nanocrystals, first-order corrections of electron-hole Coulomb and exchange i...

We investigated the electronic structure of the photosystem II reaction center (PSII RC) in relation to the light-induced charge separation process using Stark spectroscopy on a series of site-directed PSII RC mutants from the cyanobacterium Synechocystis sp. PCC 6803. The site-directed mutations modify the protein environment of the cofactors involved in charge separation (P(D1), P(D2), Chl(D1...

The photocurrent in bilayer polymer photovoltaic cells is dominated by the exciton dissociation efficiency at donor/acceptor interface. An analytical model is developed for the photocurrent-voltage characteristics of the bilayer polymer/TiO2 photovoltaic cells. The model gives an analytical expression for the exciton dissociation efficiency at the interface, and explains the dependence of the p...

We present a theoretical model for the study of exciton dynamics in J-aggregated monolayers of fluorescent dyes. The excitonic evolution is described by a Monte-Carlo wave function approach which allows for a unified description of the quantum (ballistic) and classical (diffusive) propagation of an exciton on a lattice in different parameter regimes. The transition between the ballistic and dif...

The two pulse fluorescence bleaching experiments reported in an earlier paper @J. Chem. Phys. 117, 454 ~2002!# are reanalyzed in the context of additional experiments. The fluorescence bleaching observed in that paper was originally ascribed to ground-state depletion. By analyzing the absorption saturation behavior and the magnitude of the pump–probe signal, we find that the absorption cross se...

Submitted for the MAR08 Meeting of The American Physical Society Surface Exciton-Plasmons in Carbon Nanotubes1 IGOR BONDAREV, NC Central University, KEVIN TATUR, LILIA WOODS, University of South Florida — We study theoretically the interactions of excitonic states with surface electromagnetic modes of a single-walled carbon nanotube. We use our previously developed Green’s function formalism to...

The dipole coupling strength g between cavity photons and quantum well excitons determines the regime of light matter coupling in quantum well microcavities. In the strong coupling regime, a reversible energy transfer between exciton and cavity photon takes place, which leads to the formation of hybrid polaritonic resonances. If the coupling is further increased, a hybridization of different si...

Based on the operatorial formulation of the perturbation theory, the exciton-phonon problem is revisited for investigating exciton-mediated energy flow in a finite-size lattice. Within this method, the exciton-phonon entanglement is taken into account through a dual dressing mechanism so that exciton and phonons are treated on an equal footing. In a marked contrast with what happens in an infin...