THE EFFECT OF ANNEALING ON THE OPTICAL-ABSORPTION AND ELECTRICAL-CONDUCTION OF AMORPHOUS AS24.5TE71CD4.5 THIN-FILMS

The optical absorption of as-prepared and thermally annealed As24.5Te7 1Cd4.5 thin films was measured. The optical energy gap E(0) increased from 0.58 to 0.85 eV with increasing thickness of the as-prepared film s from 58 to 125 nm. Films annealed at temperatures higher than 423 K showed a decrease in E(0). The electrical conductivity of the as-prepa red and annealed films was measured in the temperature range 80-300 K. An amorphous-crystalline transformation was observed after annealing at temperatures higher than 423 K. The results obtained are discussed on the basis of amorphous-crystalline transformations.