An electron spin resonance signal has been observed in Li-doped ZnO crystals after UV illumination at 77°K. The spectrum has axial symmetry around the c-axis of the hexagonal crystal and shows for H ⊥ c a well resolved quartet pattern because of an interaction of the unpaired spin with a Li 7 nucleus. The responsible center is probably a hole, trapped predominantly on that oxygen ion, nearest to a substitutional Li + , which is in the direction of the polar c-axis of the ZnO crystal. The intensity of the esr-signal could be quenched or enhanced by subsequent illumination with visible or infrared light. This effect was usually accompanied by charge transfer processes between the lithium center and iron impurities.
No takes yet. Share an insight, caveat, or question.
Schneider et al. (1963) studied this question.