Luminescence of high density electron‐hole plasma in CdS and CdSe in a wide temperature range

Time‐resolved spectra of the spontaneous luminescence of the high density electron‐hole plasma (EHP) in CdS and CdSe are observed in a wide range of temperature which is surely higher than the calculated critical temperature for electron‐hole liquid formation, in order to carry forward discussion on dynamic nature of the EHP previously observed in 4.2 K experiments. Spectra in the late stage are analyzed, and obtained values of the reduced bandgap energy and chemical potential are compared with those theoretically calculated for higher temperatures. The aspects of the change of the spectral shape in the late stage are hard to understand. Unfortunately, no clear conclusion is drawn on the nature of the EHP produced at 4.2 K. The only thing one can say is that the condensed electron‐hole liquid state, which is in equilibrium with the exciton state, is not realized.