Photoconductivity of textured gamma-In2Se3-xTex (0 <= x <= 0.5) thin films

Textured thin films of gamma-In2Se3 and gamma-In-2(Se,Te)(3) have been prep ared by alternate thermal evaporation of In and (Se,Te) layers on glass sub strates. The crystallization of the as-deposited films was performed by pos t-deposition heat treatment in neutral atmosphere. Photoconductivity measur ements were performed on films of both compounds in order to study the effe ct of crystalline quality and Te on the photoconductive behaviour of the fi lms. It has been shown for gamma-In2Se3 that the photocurrent is higher in films with good texture and large grains than in the films with less better quality. Moreover, the photocurrent is found to be about two orders of mag nitude higher in gamma-In-2(Se,Te)(3) films with Te amount up to 10 at.%. O n the other hand the variation of the photocurrent with incident photon ene rgy allowed us to determine the energy gap E-g of both compounds and to con firm the E-g lowering by introducing Te. (C) 2000 Elsevier Science S.A. All rights reserved.