Strong electroluminescence of Sn-implanted silicon dioxide layers

The blue-violet electroluminescence (EL) of Sn-implanted SiO2 layers thermally grown on crystalline Si has been investigated at room temperature and compared with the corresponding photoluminescence (PL) spectra. It was shown that power efficiencies up to 2.5·10-4 can be achieved, and that the power efficiency slightly decreases for high injection currents. Because of the excellent correspondence between the EL and the PL spectra we interpreted the EL as due to a radiative triplet-singlet transition of a Sn-related oxygen deficiency center. Based on the electrical measurements, we assume that the luminescence centers will be excited either by impact excitation of hot electrons moving in the conduction band of SiO2 or by field ionization of luminescence centers in conjunction with hopping conduction.