Optical temperature sensing based on the luminescence from YAG:Pr transparent ceramics

The YAG:Pr transparent ceramic was fabricated using a conventional solid-state reactive method to explore its possible application in optical thermometry. Photoluminescence and temperature-dependent luminescence were elaborately investigated under 452 nm excitation. The ceramic showed two intrinsic emission bands at 488 and 594 nm, which were attributed to characteristic Pr³⁺: ³P₀ → ³H₄ and ³P₁ → ³H₆ transitions, respectively. Down-conversion emissions from the two thermally coupled excited states of Pr³⁺ were recorded in the temperature range of 293–593 K. The Boltzmann distribution theory was adopted to interpret the temperature-dependent luminescence of Pr³⁺. The temperature sensitivity exhibited an increasing trend with the increase of temperature, typically, 0.0025 K⁻¹ at 593 K. The results indicated that the present ceramic was a promising candidate for optical temperature sensor.