The application of w-LEDs and latent fingerprint visualization with a newly developed reddish-orange YNb2VO9:Eu3+ phosphor

Abstract

In this study, a novel type of phosphor, YNb₂VO₉:xEu³⁺ (where x takes on the values of 0.5, 1, 2, 5, 10, 20, 30, 40, and 50 mol%), was synthesized through the high-temperature solid-state method. The phase purity, particle morphology, and optical properties were studied in a systematic manner. The synthesized fluorescent materials displayed high phase purity and matched the target compounds very well. The excitation spectrum of YNb₂VO₉:Eu³⁺ showed an optimal excitation wavelength at 291 nm. Observations of the emission spectrum revealed four distinct peaks, with the most prominent peak appearing at 619 nm, corresponding to the ⁵D₀→⁷F₂ radiative transition of Eu³⁺ ions. The YNb₂VO₉:5 mol%Eu³⁺ specimen was found to exhibit the most optimal optical performance despite different doping concentrations. Nearest neighbor ion interactions cause the concentration quenching effect. Notably, within the temperature range of 300–480 K, the phosphors exhibit an abnormal thermal quenching behavior alongside a substantial activation energy barrier E_a = 0.63 eV. Simultaneously, the produced white light-emitting diode (w-LED) exhibited a commendable color rendering index (R_a = 88.1), satisfactory correlated color temperature (CCT = 4553 K), and CIE chromaticity coordinates (0.345, 0.361). Moreover, latent fingerprints (LFPs) images may be displayed by YNb₂VO₉:5 mol%Eu³⁺ phosphors. The high resolution and contrast of fingerprints facilitate the recognition of level I-III features. The above experimental findings indicated that YNb₂VO₉:Eu³⁺ phosphors possessed outstanding luminescence properties and extensive application prospects.