Electroluminescence and Photoluminescence from Scored Si-Rich SiO₂ Film/p-Si Structure

Electroluminescence (EL) is observed from the Au/Si-rich SiO₂ film/p-Si diodes, in which the Si-rich SiO₂ films are scored purposely by a diamond tip. The EL intensity of the scored diode annealed at 800°C is about 6 times of that of the unscored counterpart. The EL spectrum of the unscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23 eV, while for the EL spectrum of the scored diode, an additional Gaussian band at about 3.0 eV appears, and the 1.83-eV peak increases significantly in intensity. The photoluminescence (PL) spectrum of an unscored Si-rich SiO₂ film has only one band peaking at about 1.48 eV, whereas the PL spectrum of the scored one has two bands at about 1.48 and 1.97 eV. We consider that the high-density defect regions produced by the scoring provide new luminescence centers and become some types of nonradiative centers in the Si oxide layer, which thus result in changes of the EL and PL spectra.