Photoelectric properties of highly excited ZnTe:V(Al, Sc) bulk crystals

Degenerate four-wave mixing experiments with 25-ps pulses at a wavelength of 1.06 µm have been performed in ZnTe crystals doped with deep vanadium impurity and codoped by aluminum or scandium. Complex analysis of the time resolved measurements together with exposure characteristics at various delay times of the probe beam revealed effective carrier generation from defect complexes and their subsequent recombination to Zn-vacancies in Al codoped samples. On the other hand, significantly faster carrier diffusion in Sc codoped crystal disclosed the build-up of a space charge field in deep traps through its feedback to carrier transport