Photoluminescence (PL) and Raman scattering have been used to study the defect-related growth of Ge nanocrystals during annealing of Ge+-implanted SiO2 films. Under 250 nm (similar to5 eV) photon excitation, the as-implanted sample has two strong PL bands peaked at 288 nm (4.3 eV) and 395 nm (3.1 eV), which are denoted as alpha- and beta-bands, respectively. The (beta/alpha) ratio increases with increasing implant dose. The position and linewidth of the crystalline-Ge Raman peak found approximately 300 cm(-1) after annealing at 550 degreesC remain almost unchanged by further increasing the annealing temperature up to 1100 degreesC. The annealing behaviours of Raman peaks including the extra 229, 435/485 cm(-1) ones, characteristic of amorphous Ge, Ge-Si intermixing, respectively, are closely related to those of both the absolute and relative (beta/alpha) intensities of the alpha- and beta-bands. These are discussed with reference to the Ge-related oxygen deficient defects in the films.