Photoluminescences from Si nanocrystals in ion-beam-mixed Si/SiO2 layers

Abstract

Photoluminescence (PL) from Ar-ion-beam-mixed SiO2/Si/SiO2 layers and [SiO2/Si]x3/SiO2 layers has been studied to elucidate the luminescence origins. The SiO2/Si/SiO2 layers and the [SiO2/Si] x3/SiO2 layers were irradiated by 80-keV Ar ions with a dose of 1x10(16) ions/cm(2) at room temperature (RT), which was followed by high-temperature annealing in N-2 ambient. In the case of the SiO2/Si/SiO2 layers, the PL spectra excited by the Ar-laser (457.9 nm) shelved an intense broad luminescent band with a peak near 720 nm at RT. The red-light emission is attributed to the luminescence from silicon nanocrystals produced by silicon precipitation: The formation of nanocrystals in SiO2 matrices was confirmed by cross-sectional high-resolution transmission electron microscopy. The [SiO2/Si]x3/SiO2 layers shows a broad luminescent band with a peak near 600 nm. The orange-light emission is attributed to the luminescence from the Si nanocrystals produced by ion-beam mixing and subsequent annealing at high temperature.