Photoluminescence from Si Nanocrystals Embedded in In Doped SiO2

Abstract

The luminescence properties of Si nanocrystals grown in In doped SiO2 thin films are studied. It is shown that the luminescence properties depend strongly on the In concentration. At the In concentration of smaller than 0.46 at. %, the photoluminescence (PL) intensity increases with increasing the In concentration, while the PL lifetime is nearly independent of the In concentration. This result indicates that the number of Si nanocrystals contributing to PL increases by In doping. When the In concentration exceeds 0.46 at. %, the PL intensity starts to decrease. The quenching is accompanied by the shortening of the lifetime, suggesting that nonradiative processes are introduced by In doping. However, even at a relatively high In concentration (∼3 at. %), the PL intensity is larger than that of Si nanocrystals in pure SiO2.