Defect-related infrared photoluminescence in $Ge+$-implanted $SiO2$ films

$SiO2$ films with $Ge+$ implantation at an energy of 60 keV and a dose of $1×1016 cm−2,$ followed by annealing at different temperature, exhibit a broad infrared photoluminescence (PL) at room temperature under an excitation of the 514.5 nm line of $Ar+$ laser. With increasing the annealing temperature, the intensity of the infrared PL band decreases, its full width at half maximum increases, and its energy redshifts. Spectral analysis and some experimental results from Raman scattering, electron spin resonance, and infrared spectroscopy strongly suggest that the infrared PL is mainly related to interfacial oxygen-deficient-type defects between the oxide and Ge nanocrystals.