Eu-Doped Gd₂MoB₂O₉ Phosphors for Latent Fingerprints Detection

Abstract

The luminescent powders from rare-earth ions doped oxides have been successfully used for latent fingerprint detection due to high efficiency, high contrast and low background interface. The Gd₂MoB₂O₉:Eu³⁺ phosphors with varying compositions of Eu³⁺ions were synthesized by solid state reaction method. These phosphors were investigated by X-ray diffraction (XRD), diffuse reflectance spectroscopy, photoluminescence (PL), and decay curves studies. Multiphoton relaxation decay rate and coupling strength was evaluated using phonon side band spectrum showing 0.4 mol% doped samples show less non radiative decay rate. The 0.40 mol% of Eu³⁺ ion concentration doped in the Gd₂MoB₂O₉ host lattice show highest photoluminescence emission intensity at 613 nm, in orange red region, monitored at 394 nm excitation. The Gd₂MoB₂O₉:Eu³⁺ phosphors samples were optimized to 900 °C sintering temperature and optimum milling time at 3 min in the present work. The latent fingerprints detection that developed from Gd₂MoB₂O₉:Eu³⁺ phosphors in this work exhibited clearly ridge characteristics under UV illumination. The results revealed thatGd₂MoB₂O₉:Eu³⁺ phosphors are potential practical forensic science applications.

Keywords:

• Gd₂MoB₂O₉
• phosphor
• photoluminescence
• fingerprint

Acknowledgments

N. Sangwaranatee would like to thanks Suan Sunandha Rajabhat University (Forensic Science Program) for supporting this research. The authors thanks to the Center of Excellence in Glass Technology and Materials Science (CEGM), Faculty of Science and Technology, Nakhon Pathom Rajabhat University and Faculty of Science, Silpakorn University, Thailand.

Additional information

Funding

J. Kaewkhao would like to thanks National Research Council of Thailand (NRCT) and Thailand Science Research and Innovation (TSRI) for supporting this research.