Near-Infrared Luminescence of Tb3+-Yb3+ and Ce3+-Yb3+ Co-Doped Y3Al5O12

Tb3+-Yb3+, Ce3+-Yb3+ and Ce3+-Tb3+-Yb3+ co-doped yttrium aluminum garnets (Y3Al5O12, YAG) were synthesized by conventional solid-state reactions. Upon excitations of Tb3+ ions with UV photon at 274 nm and Ce3+ ions with blue photon at 460 nm, Yb3+ emissions are observed in near-infrared region with the main peak located at 1029 nm. Based on the variations of the decay curves of Tb3+ and Ce3+ as well as energy transfer efficiencies (eta) for Tb3+ -> Yb3+ and Ce3+ -> Yb3+ processes and quantum efficiency (Q) of Yb3+ emission with Yb3+ content, the energy transfer mechanisms for the Tb3+ -> Yb3+ and Ce3+ -> Yb3+ process were discussed. Near-infrared quantum cutting process (NIR QC) is realized for the Tb3+ -> Yb3+ transfer, while for the Ce3+-Tb3+ transfer, a charge transfer process Ce3+ + Yb3+ -> Ce4+ + Yb2+ occurs, by which the Yb3+ emission is increased, but the Ce3+ emission is quenched. These materials may be potentially used in luminescent solar concentrators (LSC) to increase the efficiency of Si-based solar cells. (C) 2012 The Electrochemical Society. All rights reserved.