Luminescence Thermometry Based on the Upconversion Luminescence from the Stark Sublevels of BaY2F8:Yb3+, Tm3+ Phosphor

Ashwini K Sharma; Govind B Nair; S J Dhoble; Robin E Kroon; J J Terblans; H C Swart

doi:10.1007/s10895-023-03295-z

Luminescence Thermometry Based on the Upconversion Luminescence from the Stark Sublevels of BaY₂F₈:Yb³⁺, Tm³⁺ Phosphor

J Fluoresc. 2024 May;34(3):1039-1048. doi: 10.1007/s10895-023-03295-z. Epub 2023 Jul 14.

Authors

Ashwini K Sharma^{1

2}, Govind B Nair³, S J Dhoble⁴, Robin E Kroon⁵, J J Terblans⁵, H C Swart⁶

Affiliations

¹ Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa. ashwinikumar.vnit@gmail.com.
² Department of Physics, University, Dr. Shyama Prasad Mukherjee University, Ranchi, 834008, India. ashwinikumar.vnit@gmail.com.
³ Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa. govind1291@yahoo.com.
⁴ Department of Physics, RTM Nagpur University, Nagpur, 440033, India.
⁵ Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa.
⁶ Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa. swarthc@ufs.ac.za.

PMID: 37450083
DOI: 10.1007/s10895-023-03295-z

Abstract

Visible and near-infrared (NIR) upconversion luminescence (UCL) emissions originating from the BaY₂F₈: Yb³⁺, Tm³⁺ systems were investigated under a laser excitation at 980 nm. The BaY₂F₈:20 mol% Yb³⁺, x mol% Tm³⁺ and BaY₂F₈: y mol% Yb³⁺, 0.5 mol% Tm³⁺ phosphors showed prominent UCL at 800 and 810 nm. The optimized doping concentrations of Yb³⁺ and Tm³⁺ in the BaY₂F₈ host matrix were evaluated, their spectroscopic properties were determined, and studies on their temperature-dependent behaviour were carried out. The temperature-sensing properties were studied by generating the fluorescence intensity ratio (FIR) of the UCL peaks originating from the thermally-coupled energy levels of the Tm³⁺ ions. The Stark sublevels of ¹G₄ level of Tm³⁺ ions were utilized to estimate the temperature-sensing abilities of the phosphor.

Keywords: Tm3+; Upconversion; fluoride; luminescence thermometry; phosphor.

Abstract

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