Acoustic absorption and electron-phonon interaction in CdSe

The acoustic-absorption coefficient was measured at 25, 35, 45 MHz in CdSe at liquid-nitrogen temperature. Measurements were performed both during the illumination of the smaple and in the time subsequent to the end of the illumination. It was shown that, in suitable conditions, a secondary peak of absorption takes place after the light pulse. The experimental results are explained in terms of electron-phonon interactions following a calculation due to Lommes and Weichman, and are related to the behaviour of the sample with respect to the phenomenon of residual conductivity.