(Si/SiO2)n multilayers and microcavities for LED applications

We formed (Si/SiO2)(n) multilayers with Si-layers thinner than 2 nm using CMOS processing. These samples give room temperature emission ranging from 650 to 1000 nm. The analysis of photoluminescence spectra and the decay dynamics identifies exciton recombination in quantum-confined low-dimensional silicon as the mechanism. (Si/SiO2), multilayers in the central region of lambda and lambda /2 microcavities consisting of dielectric Bragg reflectors (DBRs) formed by lambda /4 stacks of [SiO2/Si](n) (n = 2-3) layers and a SiO2 spacer, show both enhancement and narrowing of the emission. The quality factor (e) is higher for the h-type cavity. Multilayers inside MOS capacitors (M = Al, Au) show electroluminescence bands ranging from the blue to the NIR. The main contribution to the electroluminescence is recombination of hot electrons in the Si-substrates. (C) 2001 Published by Elsevier Science B.V.