Upconversion luminescence based temperature sensing properties and anti-counterfeiting applications of GdNbO4:Tm3+/Yb3+ phosphor

Madan M Upadhyay; Neeraj Kumar Mishra; Kaushal Kumar

doi:10.1016/j.saa.2023.123333

Upconversion luminescence based temperature sensing properties and anti-counterfeiting applications of GdNbO₄:Tm³⁺/Yb³⁺ phosphor

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Jan 5:304:123333. doi: 10.1016/j.saa.2023.123333. Epub 2023 Sep 1.

Authors

Madan M Upadhyay¹, Neeraj Kumar Mishra¹, Kaushal Kumar²

Affiliations

¹ Optical Materials & Bio-imaging Research Laboratory, Department of Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
² Optical Materials & Bio-imaging Research Laboratory, Department of Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India. Electronic address: kkumar@iitism.ac.in.

PMID: 37690402
DOI: 10.1016/j.saa.2023.123333

Abstract

Pure monoclinic phase GdNbO₄:Tm³⁺/Yb³⁺ phosphor was prepared using solid state reaction method for upconversion emission, optical thermometry, latent fingerprints visualization and anti-counterfeiting applications. The prepared phosphor exhibits colour tunability with temperature variation (from blue to almost white) and good suppression of thermal quenching. The temperature sensing characteristic from thermally and non-thermally coupled levels of Tm³⁺ ion were investigated using the fluorescence intensity ratio (FIR) approach. The result shows that the sensitivity for non-thermally coupled level is about ∼ 45 times higher than thermally coupled level. Latent fingerprint detection on various surfaces and anti-counterfeiting ink application were also shown upon 980 nm laser diode excitation. Above results indicate that the prepared GdNbO₄:Tm³⁺/Yb³⁺ phosphor have applicability in the field of frequency upconversion, optical thermometry, color tunable devices, latent fingerprint visualization and anti-counterfeiting applications.