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

Abstract.

Photoconductivity and photorefractive two-wave-mixing in a diffusion regime have been analyzed in a germanium-doped Cd_0.99Zn_0.01Te crystal at λ=1.064 μm. Temporal responses present a transient enhancement depending on total illumination and temperature. This enhancement depends also on the initial illumination present on the crystal. Steady-state photorefractive gain is rather high and presents an intensity–temperature resonance phenomenon. In addition, preliminary measurements have been performed at λ=1.55 μm. More classical behavior has been observed and a relatively lower photorefractive gain has been measured. We interpret these differences in terms 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.