ScholarWorks@성균관대학교

초록

Optical materials play an important role in non-contact thermometers due to their non-contact, advantageous rapid, and high precision properties. In this study, we successfully synthesized niobate Ca2LaNbO6 (CLNO) phosphors doped with rare earth ions Ln3+ (Ln = Eu/Tb/Dy), determined the optimal doping concentration of Eu3+, Tb3+, and Dy3+ activators to be 40%, 8%, and 4%, respectively, while systematically investigating the concentration quenching mechanisms. Under ultraviolet excitation, the down-conversion CLNO:Ln3+ phosphors emit visible light originating from the characteristic f-f transitions of the Ln3+ ions. The luminescence intensities ratio (LIR) corresponding to the radiation transitions energy levels of [Eu3+: (5D0→7F2)/(5D0→7F4)], [Tb3+: (5D3→7F6)/(5D4→7F5)], and [Dy3+: (4F9/2 → 6H13/2)/(4F9/2 → 6H15/2)] serve as effective indicators for temperature sensing. These relationships between LIR and temperature can be effectively fitted by the exponential function [ LIR = Aexp(B/T) + C ], and the R-squared (R2) are 0.9842, 0.9989, and 0.9878 respectively. The corresponding temperature sensitivities reached 0.6 %K−1, 9.4 %K−1, and 1.6 %K−1, respectively. Therefore, the prepared down-conversion phosphor indicates a potential application in non-contact optical temperature sensing under ultraviolet excitation.

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