Enhancing electroluminescence from Au/nanoscale Si-rich SiO2 film/p-Si by doping Al into the SiO2 film and gamma-ray irradiation

Doping Al into the nanoscale Si-rich SiO2 (NSS) films subsequently annealed at temperatures lower than similar to 700 degreesC made the EL intensity o f Au/NSS/p-Si samples increase by a factor of 4-6, but did not change its E L peak wavelength. Doping Al into NSS films subsequently annealed at temper atures higher than similar to 700 degreesC made the EL intensities of Au/NS S/p-Si samples increase by a factor larger than 6 and the EL peaks redshift evidently, gamma -ray irradiation has very similar effects in increasing a nd redshifting the EL spectra of Au/NSS/p-Si. The currents of Au/NSS/p-Si s amples with NSS/p-Si annealed at various temperatures under a definite forw ard bias were invariant or increased in the gamma ray irradiation process. However, the currents of Au/NSS:Al/p-Si samples with NSS:Al/p-Si annealed a t temperatures smaller than similar to 700 degreesC under the same definite forward bias decreased in the gamma -ray irradiation process. The experime ntal facts can be interpreted qualitatively if the main origin of EL is att ributed to defects and/or impurities in the NSS films. (C) 2001 Elsevier Sc ience B.V. All rights reserved.