Photo-electronic properties of solution-grown CdSe films

Abstract

Pure CdSe films have been deposited on glass substrates by a solution growth technique. Spectral distribution of refractive index (n) and absorption coefficient (α) has been calculated. The films have a direct energy gap of 1.74 eV. These films have been sensitized by heating in air, and maximum value of light to dark current ratio m^~2 × 10³ at 50 mW-cm^-2 white light illumination has been obtained. The maximum peak of spectral sensitivity is at 0.7 μm. Trap density m10¹⁷-10¹⁸traps cm³ eV in the energy range 0.21-0.26 eV has been estimated. Properties of the sensitizing centres have been studied and are observed to be similar to those of single crystals.