Dual-emitting Ce3+, Tb3+ co-doped LaOBr phosphor: Luminescence, energy transfer and ratiometric temperature sensing

A series of broadband UV-excited and dual-emitting LaOBr: Ce3+, Tb3+ phosphors were synthesized by solid state reaction. Luminescent property, energy transfer behavior, thermal stability and ratiometric temperature sensing performance were investigated. Under single NUV excitation, LaOBr: Ce3+, Tb3+ exhibited both blue Ce3+ emission band and sensitized green Tb3+ emission peak, and the color of high-brightness emission can be tuned from blue to green by changing Ce3+/Tb3+ ratio. The Ce3+-Tb3+ energy transfer efficiency is determined to be 87.7% with critical distance of 12.6 angstrom. The application potential of LaOBr: Ce3+, Tb3+ in optical thermometry was studied by exploiting the temperature sensitivity of the fluorescent intensity ratio (blue/green). It is found that fluorescent intensity ratio of LaOBr: Ce3+, Tb3+ displays linear correlation with temperature in a wide range of 293-433 K with high sensitivity of 0.42% K-1, indicating that it could be a good candidate for ratiometric optical thermometry. (C) 2016 Elsevier B.V. All rights reserved.