Transformation from raman scattering to photoluminescence at the c exciton of CdSe

In studying resonant Raman scattering around the C exciton of the wurtzite semiconductor CdSe we have observed a Raman mode with an unusual dependence on the incident photon frequency. As the incident photon is tuned across the C exciton, this Raman mode gradually broadens and shifts in frequency until it becomes a photoluminescence peak centered at the C exciton frequency. A phenomenological theory is proposed to explain the behavior of this mode by the presence of a "bottleneck" in the decay of resonant intermediate states involved in the scattering of this mode. © 1976 The American Physical Society.