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

摘要

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 Er~(3+) ions in surrounding SiO_2. 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 Er~(3+) ions was achieved and a decrease of the decay time of the photoluminescence at 1.5 μm was observed. Possible mechanisms of the shortening of the Er~(3+) ion lifetime are discussed.