PHOTOLUMINESCENCE DYNAMICS OF CO-DOPED ZN1-XCDXSE AND ZNSXSE1-X CRYSTALS

Intra-shell d-d relaxation processes of Co2+-centres are investigated by means of time-integrated and time-resolved photoluminescence spectr oscopy. The composition dependence of the luminescence and the decay o f the Co L-line in ZnCdSe and ZnSSe alloys is presented for the first time. Additionally, new Co-related infrared luminescence lines were ob served near 1.6 eV. Taking into account the energy position of the L-l ine and the relaxation dynamics of the green and the infrared luminesc ence, the L-line is explained as an internal doublet-quartet d-d trans ition of the Co-centres. (C) 1998 Elsevier Science B.V. All rights res erved.