| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1494199 | Optical Materials | 2014 | 5 Pages |
•Thermal stability and annealing of Eu doped YAG are evaluated by PL spectra.•Color of Eu doped YAG varies with O2 concentration and annealing.•PL at 590, 607, 624, 647 and 709 nm from Eu3+ are observed from Eu doped YAG.•Temperature dependence of PL is improved by annealing.•Oxidation of Eu2+ is responsible for de-coloration and temperature dependence of PL.
Eu2O3 doped Y3Al5O12 (YAG) crystals have been grown using a floating zone technique and evaluated thermal stability and annealing behavior of PL for a fluorescence thermo-sensor application. Color of the crystals grown varies from deep purple to colorless with O2 concentration of the growth atmosphere and annealing in air. Photoluminescence (PL) peaking at λ = 590, 607, 624, 647 and 709 nm due to Eu3+ ions are observed from the crystals under UV excitation. Anomalous temperature dependence of PL intensity, which is observed in as-grown crystals, is improved greatly by annealing through the heat cycle. From annealing behavior of optical absorption spectra, residual Eu2+ ions are suggested to be responsible for the de-coloration and the improvement of anomalous temperature dependence of Eu doped YAG crystals.
