TIME-RESOLVED ZERO-FIELD OPTICALLY DETECTED MAGNETIC-RESONANCE STUDY OF THE (CU-LI)V NEUTRAL DEFECT COMPLEX IN GAP

A study of the lowest excited triplet state T0 of the neutral hole-attractive defect complex (Cu-Li)V in GaP with the aid of both cw and time-resolved optically detected magnetic resonance in zero magnetic field is presented. From the cw experiments, the zero-field splitting of T0 is determined, and it is concluded that the (Cu-Li)V defect is of C2v or lower symmetry. From time-resolved microwave-induced delayed phosphorescence experiments, information on the dynamics of population and decay of the T0 substates is obtained. A large difference in the total and radiative decay rates of the spin levels is found. The interpretation of these results in terms of spin-orbit coupling is not yet possible because a detailed model for the electronic structure of the (Cu-Li)V defect is lacking. It is observed that the creation of the photoexcited triplet state via capture of a conduction electron by the ionized defect does not show any spin selectivity, in contrast to the decay from the triplet sublevels. © 1990 The American Physical Society.