Exciton Donor-like

Ekimov A. 1., Efros A. L., Ivanov M. G., Onushenko A. A. and Shumilov S. K. (1989), Donor-like exciton in zero-dimension semiconductor structures . Solid State Comm. 69, 565-568. 

JC Marini, B Stebe, E Kartheuser. Influence of the electron-phonon interaction on a donor like exciton in a semiconductor microsphere. Solid State Commun 87 435-437, 1993. 

For dilute solutions of essentially independent donor and acceptor molecules the Forster or resonance interaction is quite important in molecular aggregrates and in molecular crystals exciton interactions are likely to be important. When the interaction is strong the excitation is not localized on the donor or acceptor but is spread over both. If larger aggregrates are involved, the excitation can be spread over many molecules/33-3 This can easily be seen for the case of a dimer where the donor and acceptor are... 

The mechanism of control with multipulse excitation is likely due to dynamics of the carotenoid donor. The presumably incoherent EET process [1] would not support the observed dependence on the carrier phase via the parameter c. Furthermore, the control effect does not suffer from annihilation at higher excitation intensities [2], as would be characteristic for the delocalised excitons in the B850 ring [1], However, it is well known that femtosecond pulses populate higher ground state vibrational levels by impulsive Raman scattering (IRS) [4], and that the periodic phase modulation (Eq. 1) makes IRS selective for specific vibrations... 

Should a system contain donor and acceptormoieties, an exciton like behavior can be observed when the charges recombine. Again, effective mass theory can present us with the energy of the observed transition, as shown in equation (5) ... 

The soliton concept is likely to prove fruitful in many aspects of photochemistry especially where organized systems are involved, It has been proposed that charge transfer excitons in mixed-stack donor-acceptor compounds exist in a variety of solitonic states . In this effect charge transfer states couple to lattice phonons in the crystal lattice to form the comparatively stable solitons. 

---