Electroluminescence and photoluminescence of Ge+-implanted SiO2 films thermally grown on crystalline silicon

Electroluminescent devices have been fabricated based on Ge+-implanted SiO2 films thermally grown on crystalline silicon. Both room-temperature electroluminescence and photoluminescence spectra are found to have three luminescent bands peaked at 3.1, 2.1, and 1.6 eV. The electroluminescent devices have onsets for emission under forward bias of 5 V and under reverse bias of −13 V. Its emission is stable and reproducible. Spectral analyses suggest that the electroluminescent excitation of the 3.1 eV band may be related to the impact ionization by hot electrons, whereas that of the 2.1 and 1.6 eV bands to the radiative recombination of hole-electron pairs.