Abstract

We report on the first observation of the photorefractive effect in ZnTe. The photorefractive response was observed over the broad wavelength range of 0.6-1.3 μm, and suggest ZnTe to be a good candidate for semiconductor laser applications around 0.8 μm. The sample we investigated was doped with a starting vanadium concentration of 10¹⁹ cm^-3 and was grown by physical-vapor-transport (PVT). The absorption tail of this sample extended from the band gap around 0.55 μm to beyond 1.5 μm. Photoluminescence studies at 5 K showed broad peaks around 1.6, 1.065 and 0.825 eV. Two beam-coupling measurements at 0.63 μm suggest an effective trap density of 1.4 x 10¹⁴ cm^-3 and a value of 4.3 pm/V for the ξr₄₁ value, where r₄₁ is the electrooptic coefficient and ξ is the electron-hole competition factor. The photorefractive response time of ZnTe is fast; we have observed a grating formation time of 15 μsec at 4.7 W/cm³ (λ=0.63 μm) which is comparable to GaAs at 1.06 μm. The intensity dependence of the response time was sub-linear which, together with the photoluminescence spectra, suggests that multiple levels are taking part in the photorefractive effect.

© 1991 Optical Society of America