Photoluminescence properties of sol–gel derived SiO2 layers doped with porous silicon

Abstract We proposed and studied a new light emitting material based on silicon nanocrystals (Si-nc). The new material was fabricated using a low cost way by incorporating Si-nc into a sol–gel derived SiO 2 matrix. The Si-nc were prepared (i) by electrochemical etching of monocrystalline Si wafers and (ii) pulverizing the obtained porous silicon film. The porous silicon powder was then dispersed in the SiO 2 sol. After solidification, we obtained transparent and self-supporting SiO 2 layers of about 1 mm thickness containing Si nanocrystals. The sol–gel layers exhibit bright red photoluminescence (PL) under UV lamp excitation at room temperature. This novel method circumvents the usual Si + -implantation step. We present first basic experimental studies of the PL properties of these sol–gel derived SiO 2 layers and compare them with that of as-prepared porous silicon. We mention also observation of a non-linear behavior in the PL spectra. We emphasize potential advantages of this technology compared to the standard Si + -implanted SiO 2 layers.