Effect of implantation and annealing conditions on the photoluminescence emission of Si nanocrystals ion beam synthesised in SiO2

In this article, we present a systematic study of the evolution of photoluminescence (PL) emission of Si nanocrystals with elaboration conditions. Si nanocrystals synthesised in SiO2 by ion implantation and annealing at 1100 degrees C show a wide (0.3 eV) and a very intense PL emission centred at 1.5-1.7 eV, linked to the presence of the nanocrystals. The intensity of this emission shows a typical behaviour with the annealing time, with a fast transitory increase to reach an asymptotical saturation. There is a linear increase of the PL intensity at saturation with the dose. Two regimes are clearly observed for the evolution of the PL energy position as a function of the annealing time for different peak supersaturations (s): (i) for s < 5%, there is a decrease transient followed by a saturation state of the maximum peak energy, and (ii) for s greater than or equal to 5% the PL energy presents an increase transient followed by a saturation state. (C) 2000 Elsevier Science Ltd. All rights reserved.