Optical and electrical properties of Ge-implanted SiO2 layers on n-Si and p-Si

Ge ions of 100 keV were implanted into a 120 nm-thick SiO2 layer on n-Si at room temperature while those of 80 keV were into the same SiO2 layer on p-Si. Samples were, subsequently, annealed at 5008C for 2 h to effectively induce radiative defects in the SiO2. Maximum intensities of sharp violet photoluminescence (PL) from the SiO2/n-Si and the SiO2/p-Si samples were observed when the samples have been implanted with doses of 1 1016 and 5 1015 cmÿ2, respectively. According to current±voltage (I±V) characteristics, the defect-related samples exhibit large leakage currents with electroluminescence (EL) at only reverse bias region regardless of the type of substrate. Nanocrystal-related samples obtained by an annealing at 11008C for 4 h show the leakage at both the reverse and the forward region. # 2001 Elsevier Science B.V. All rights reserved