Luminescence properties of Ge implanted SiO2:Ge and GeO2:Ge films

Abstract We have investigated cathodeluminescence (CL) of Ge implanted SiO 2 :Ge and GeO 2 :Ge films. The GeO 2 films were grown by oxidation of Ge substrate at 550 °C for 3 h in O 2 gas flow. The GeO 2 films on Ge substrate and SiO 2 films on Si substrate were implanted with Ge-negative ions. The implanted Ge atom concentrations in the films were ranging from 0.1 to 6.0 at%. To produce Ge nanoparticles the SiO 2 :Ge films were thermally annealed at various temperatures of 600–900 °C for 1 h in N 2 gas flow. An XPS analysis has shown that the implanted Ge atoms were partly oxidized. CL was observed at wavelengths around 400 nm from the GeO 2 films before and after Ge − -implantation as well as from SiO 2 :Ge films. After Ge − -implantation of about 0.5 at% the CL intensity has increased by about four times. However, the CL intensity from the GeO 2 :Ge films was several orders of magnitude smaller than the intensity from the 800 °C-annealed SiO 2 :Ge films with 0.5 at% of Ge atomic concentration. These results suggested that the luminescence was generated due to oxidation of Ge nanoparticles in the SiO 2 :Ge films.