Electroluminesence from Au/(SiO2/Si/SiO2) nanoscale double-barrier/n(+)-Sistructure

The (SiO2/Si/SiO2) nanoscale double-barrier/n(+)-Si structures with Si laye rs of various thicknesses were fabricated by the two-target alternative mag netron sputtering technique. The thicknesses of the Si layers in the struct ures are from 2 nm to 4 nm with an interval of 0.2 nm. The control samples with Si layers of 0 nm were also made. After these structures were annealed at 600 degrees C in a N-2 ambient for 30 min, electroluminescence (EL) fro m the Au/SiO2/Si/SiO2/n(+)-Si structures were observed under reverse biases (n(+)-Si is biased to positive). It was found that the current and EL inte nsity synchronously swing with increasing Si layer thickness. All EL spectr a of the samples can be decompounded into two Gaussian luminescent spectra with peaks at 1.85 eV (670 nm) and 2.26 eV (550 nm). Analysis of experiment al results indicates that the EL orginates from the recombination of electr ons and holes, which are produced in an avalanche process in the Au/(SiO2/S i/SiO2) nanoscale double-barrier/n(+)-Si structure, via luminescence center s in the SiO2 layers.