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

Abstract We formed (Si/SiO 2 ) 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/SiO 2 ) n multilayers in the central region of λ and λ/2 microcavities consisting of dielectric Bragg reflectors (DBRs) formed by λ/4 stacks of [SiO 2 /Si] n ( n = 2–3) layers and a SiO 2 spacer, show both enhancement and narrowing of the emission. The quality factor ( Q ) is higher for the λ-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.