PHOTOREFRACTIVE RESPONSE OF CDTE-V UNDER AC ELECTRIC-FIELD FROM 1 TO 1.5 MU-M

The ac field technique leading to the enhancement of the photorefracti ve effect is applied to vanadium-doped cadmium telluride. Net photoref ractive gain is obtained for the three wavelengths studied: 1.06 mu m, 1.32 mu m and 1.55 mu m. A change in the sign of the photorefractive gain between 1.06 mu m and 1.55 mu m is observed, which represents the first evidence of an electron-hole competition in this material. Theo retical interpretation is performed using an extension of the ac field theoretical model with bipolar conduction.