CHARACTERIZATION OF (AS.TE)(1-X)SE-X THIN-FILMS

Optical absorption at room temperature and electrical resistivity at t emperatures between 200 and 320 K for (As.Te)(1-x)Se-x thin films (whe re x = 0.20, 0.23, 0.27, 0.32 and 0.44) have been studied. Increasing the Se content was found to increase the optical energy gap and the ac tivation energy for conduction of the investigated films. The optical energy gap of the As0.40Te0.40Se0.20 films was increased up to 1.21 eV by increasing the film thickness to similar to 120 nm, while thermal annealing at 480 K reduced it down to 0.83 eV. The decrease of the opt ical gap is discussed on the basis of amorphous-crystalline transforma tions.