Luminescence and X-ray diffraction studies of Ge nanocrystals in amorphoussilicon oxide

Ge nanocrystals embedded in a-SiO2 films have been synthesized by rapid the rmal annealing. Under excitation sources of different wavelengths, three ph otoluminescence (PL) peaks at 1.8, 2.2 and 3.1 eV were observed. A forming gas anneal on the samples resulted in a reduction of the intensity of the P L peaks. Studies of the annealed samples by X-ray diffraction revealed the formation of GeO2 and Ge nanocrystals in the rapid thermal annealed system. The origin of the PL peaks is suggested to be due to defect related mechan ism. (C) 2000 Elsevier Science S.A. All rights reserved.