Instability of Cl-Related Deep Defects in ZnSe

We have studied the instability of Cl-related deep defects in ZnSe by means of far-infrared magnetooptical absorption measurements. Zeeman absorption corresponding to 1s–2p+ transition of electrons bound to Cl donors has been observed under photoexcitation. The absorption intensity increases with the lapse in time after photoexcitation, and saturates in approximately 1 h. These results suggest the presence of deep states in the midgap, which are evidently associated with its photoinduced transformation.