HIGHLY EFFICIENT SENSITIZING OF ERBIUM ION LUMINESCENCE IN SIZE-CONTROLLED NANOCRYSTALLINE SI/SIO2 SUPERLATTICE STRUCTURES

Abstract

Comparative studies of photoluminescence (PL) of undoped and Er-doped size-controlled nanocrystalline Si/SiO2 superlattice structures show that the optical excitation of Si nanocrystals can be completely transferred to the Er3+ ions in surrounding SiO2, resulting in a strong PL line at 1.5 μm. The PL yield of the Er-doped structure increases for higher photon energy of excitation and for smaller nanocrystal sizes. This highly efficient sensitizing of the Er-related PL is explained by a strong coupling between excitons confined in Si nanocrystals and neighboring Er3+ ions in their upper excited states.