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: Ce 3+ , Tb 3+ 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: Ce 3+ , Tb 3+ exhibited both blue Ce 3+ emission band and sensitized green Tb 3+ emission peak, and the color of high-brightness emission can be tuned from blue to green by changing Ce 3+ /Tb 3+ ratio. The Ce 3+ -Tb 3+ energy transfer efficiency is determined to be 87.7% with critical distance of 12.6 Å. The application potential of LaOBr: Ce 3+ , Tb 3+ 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: Ce 3+ , Tb 3+ 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. [ABSTRACT FROM AUTHOR]