PHOTOACTIVE DEFECT-RELATED I-V LUMINESCENCE LINE OBSERVED IN ZNSE GAAS LAYERS GROWN BY MOLECULAR-BEAM EPITAXY/

Intensity of a photoluminescence line named I-V observed at the near b and-edge region for undoped ZnSe/GaAs is found to increase exponential ly with the time duration of photoexcitation. The rise time is unexpec tedly long, i.e. several hundreds of seconds under low excitation inte nsity and at low temperatures, and decreases with increasing excitatio n intensity or temperature. Experimental results lead us to suggest th at the luminescence center responsible for the I-V line is the Se vaca ncy which captured one or two electrons.