Luminescence of SiO₂ Film Implanted with Ge Negative Ions

Abstract

The cathodeluminescencs (CL), photoluminescence (PL), and electroluminescence (EL) properties of Ge implanted SiO₂ films (SiO₂:Ge) were investigated. The SiO₂ films on Si substrate were implanted with Ge-negative ions. The implanted Ge atom concentrations in the films were 3 and 6 at. %. Ge nanoparticles were formed in the SiO₂ films after annealing. CL, PL and EL were observed at wavelengths around 400 nm from the SiO₂:Ge films. CL of GeO₂ films were also investigated. The CL intensity from the GeO₂ films is obviously lower than that from the SiO₂:Ge films with 6 at.% of Ge atomic concentration. Strong EL from large area of the films was not only to be easily seen with naked eye but also to be measured its wavelength. Ooperating voltage was an order of magnitude lower and the emitting area was two orders of larger than those reported previously. These results suggested that annealing of SiO₂:Ge films in moderate oxidative atmosphere is suitable method for the strong luminescence due to Ge-related oxygen deficient center (Ge-ODC).