YAG:Tb@YAG:Pr Single Crystalline Dual-Layer Phosphor. An Alternative Approach to Multimodal Wide Range Luminescence Thermometry

The SC-YAG:Tb@YAG:Pr-SCF composite epitaxial structure consisting of a 1 mm thick single crystal substrate of YAG:Tb garnet and a thin (9 mu m) single crystalline film of YAG:Pr garnet is fabricated, and its luminescent properties are examined toward luminescence thermometry. The possibility to efficiently excite, individually or simultaneously, the Tb3+ and Pr3+ dopants by their intense allowed 4f -> 5d transitions is executed to reach relative thermal sensitivity higher than 1% K-1 over the range of temperatures as wide as 100-625 K and above 0.5% K-1 over 13-650 K. The obtained results demonstrate that using intra- and inter-configurational emission transitions of Pr3+ and other lanthanides makes it possible to design wide-range luminescence thermometers with high sensitivity spanning the entire operating limits.