Carrier-mediated 1.55 μm photoluminescence from single Er3+ center in SnO2 nanocrystals

We report the successful incorporation of Er3+ ions into SnO2 nanocrystals via a solvothermal method, with a resulting Er3+ concentration of the order of 10(19) cm(-3). Upon excitation above the SnO2 bandgap at 300 nm, intense and well-resolved Er3+-related photoluminescence (PL) at 1.55 mu m was observed at room temperature. The results of PL excitation and ultraviolet/visible diffuse reflectance spectra indicate that the excitation is a carrier-mediated process with an energy transfer from the SnO2 host to Er3+. For the above-gap excitation, only a single type of Er3+ luminescence center located at a centrosymmetric site was identified. The near-infrared luminescence dynamics and the weak PL thermal quenching of Er3+ were also revealed. (C) 2009 Optical Society of America