BLUE AND RED PHOTOLUMINESCENCE FROM GE-FILMS AND ITS MULTIPLE MECHANISM( IMPLANTED SIO2)

Under violet excitation, a strong blue band and a broad red band are e mitted simultaneously from the Ge nanocrystal embedded SiO2 films fabr icated by Ge+ implantation and annealing. The blue band exhibits a com plex annealing behavior, and the photoluminescence excitation spectral analysis indicates that it results from a combination of several impl antation-induced deficient centers. The peak position of the red band shifts from 600 to 640 nm when the mean size of Ge nanocrystals increa ses from 4.3 to 6.7 nm, suggesting that the red band comes from the ra diative recombination of excitons confined in Ge nanocrystals. (C) 199 8 American Institute of Physics. [S0003-6951(98)02739-9].