COHERENT RAMAN-SPECTROSCOPY AND TIME-RESOLVED EMISSION OF CDSE QUANTUM DOTS IN GLASS

This paper reports on experimental results about the electron-phonon c oupling in few nm sized CdSe quantum dots (QDs) embedded in a glass ma trix. We compare results from non-degenerate four-wave mixing (NDFWM) with those from time resolved photoluminescence (PL). In NDFWM, we rep ort for the first time on a distinct enhancement of \chi((3))\(2) for beam detunings near the bulk LO-phonon energy. We extend Yajima's theo ry on NDFWM(1)) to the case of an inhomogeneously broadened multi phon on system including Coherent Raman Scattering processes. The theory gi ves reasonable agreement with the data and enables us to deduce the Hu ang-Rhys parameter and the relevant relaxation times from the experime nt. In PL, the corresponding Franck-Condon progression of the electron -hole (e-h) pair groundstate is clearly resolved. We compare the coupl ing constants and the homogeneous line widths deduced from both experi ments and demonstrate the effect of photostructural changes upon the r elaxation times.