DEPHASING OF ACCEPTOR-BOUND EXCITONS IN II-VI SEMICONDUCTORS

Degenerate four-wave-mixing experiments (DFWM) at the neutral acceptor bound exciton complex in CdS and ZnSe are reported. ps- as well as fs -spectroscopy are carried out to investigate the dephasing processes a t this complex. The results are discussed concerning scattering of fre e excitons, phonons, and interactions with impurity centers. Higher or ders of diffraction in the DFWM process are modeled within the density matrix equations for noninteracting two-level systems including propa gation effects. From nonlinear quantum beat spectroscopy tile binding energies of the acceptor bound biexciton in CdS and ZnSe are estimated .