Pico-second spectroscopy of highly excited CdSe and CdS—II high density electron-hole plasma

A new luminescence line characterized by a broad spectral width appears under intense pico-second pulse excitation at 4.2 K in both CdSe and CdS. With increasing excitation density the peak of the line shifts to lower energies and the spectral width becomes broader. Just opposite changes are observed with the lapse of time after excitation. It is concluded that the line is due to high density electron-hole plasma.