Novel approach for synthesizing Ge fine particles embedded in glass by ion implantation: Formation of Ge nanocrystal in SiO2-GeO2 glasses by proton implantation

Nanometer-sized crystalline Ge colloid particles have been formed by implantation of protons into substrate glasses having a composition of 1 GeO2-9SiO2 to a fluence of 1×1018 cm−2 at an energy of 1.5 MeV at room temperature without post-thermal annealing. Intensities of the absorption band due to Ge particles reach a maximum at ∼30 μm from the surface and their depth profile is close to that of the electronic energy loss. No formation of Si particles was observed in SiO2 or SiO2:GeO2 glasses implanted with protons at the same conditions and fluence.