Influence of thermal annealing on the intensity of the 1.54-mu m photoluminescence band in erbium-doped amorphous hydrogenated silicon

Erbium-doped a-Si:H films are prepared by magnetron sputtering of a Si-Er t arget at a deposition temperature of 200 degrees C. The films are then subj ected to cumulative thermal annealing. A sharp increase (similar to 50-fold ) in the photoluminescence intensity at a wavelength of 1.54 mu m is observ ed after a 15-min anneal at 300 degrees C in a nitrogen atmosphere. At an a nneal temperature greater than or equal to 500 degrees C the photoluminesce nce signal decreases essentially to zero. The influence of thermal annealin g processes is discussed in the context of the model of partial transformat ion of the structural network of amorphous a-Si(Er):H films. (C) 1999 Ameri can Institute of Physics. [S1063-7826(99)02201-2].