Multiple magnification effects of Ce3+ ions on near-infrared persistent luminescence of Cr-doped LaAlO3

Ce3+/Cr3+ co-doped LaAlO3 for near-infrared (NIR) long lasting phosphors were synthesized through solid-state reaction. Incorporation of Ce3+ ions into Cr3+-doped LaAlO3 significantly enhanced the NIR persistent luminescence by more than one order of magnitude compared with LaAlO3 doped with Cr3+. Detailed analysis of the photoluminescence, photoluminescence excitation, and Thermo-luminescence spectra, as well as the persistent decay behavior of Ce3+/Cr3+ co-doped LaAlO3, indicated that the improvement of NIR persistent luminescence at around 735 nm (Cr3+: E-2 ->(4)A(2) transition) is not only originated from a persistent energy transfer process from Ce3+ ions to Cr3+ ions, but also attributed to the extra efficient traps created by incorporation of Ce3+ ions. The current work develops an alternative approach toward the efficient NIR Cr3+-doped non-gallate longpersistence phosphors. (C) 2016 Optical Society of America