Light emission from erbium-doped nanocrystalline silicon/silicon dioxide layers under strong optical excitation

Photoluminescence properties of Er-doped nanocrystalline Si/SiO2 structures have been investigated under strong optical excitation. The energy of optical excitation of Si nanocrystals was shown to be almost completely transferred to Er3+ ions in surrounding SiO2. It was found that at high pump intensity the energy transfer process competes successfully with nonradiative Auger-recombination in Si nanocrystals. At high excitation level the population inversion of Er3+ ions was achieved and a decrease of the decay time of the photoluminescence at 1.5 mu m was observed. Possible mechanisms of the shortening of the Er3+ ion lifetime are discussed.