Stationary and transient analysis of photoconductivity and photorefractivity in CdZnTe : Ge

Photoconductivity and photorefractive two-wave-mixing in a diffusion regime have been analyzed in a germanium-doped Cd0.99Zn0.01Te crystal at lambda = 1.064 mu m. Temporal responses present a transient enhancement depending o n total illumination and temperature. This enhancement depends also on the initial illumination present on the crystal. Steady-state photorefractive g ain is rather high and presents an intensity-temperature resonance phenomen on. In addition, preliminary measurements have been performed at lambda = 1 .55 mu m. More classical behavior has been observed and a relatively lower photorefractive gain has been measured. We interpret these differences in t erms of multiple captures induced by at least two deep traps and a shallow trap located within the band gap of the material. Experimental results show this material to have very promising prospects for further photorefractive developments.