PHOTOLUMINESCENCE AND PHOTOCONDUCTIVITY OF CdS:Li SINGLE CRYSTALS.

An investigation was made of the photoluminescence of CdS:Li single crystals. A wide structure-free band at lambda //m equals 540 nm was attributed to the recombination of photocarriers at donor-acceptor pairs composed of a deep donor and a shallow acceptor (possibly Li). A band at lambda //m equals 522 nm was not the first phonon replica of the frequently observed green luminescence but a new band due to the introduction of Li, which was superimposed on the phonon replica but had a much higher intensity. An investigation of the excitation spectra of the green and orange bands and of the photocurrent established that the luminescence centers responsible for the lambda //m equals 522 nm band were largely complexes, which included an orange luminescence center and Li atoms.