Surface modification of Mg2InSbO6:Eu3+ phosphors and applications for white light-emitting diodes and visualization of latent fingerprint

Due to outstanding optical characteristics of phosphors, they have recently been applied to various fields, such as solid-state lighting, forensic science, and laser technology. Herein, a series of Mg2InSbO6:xEu(3+) (x = 0.005-0.25) phosphors with pure red emission were prepared via high-temperature solid-state reaction. Under near-ultraviolet 395 nm excitation, photoluminescence spectra of Mg2InSbO6:Eu3+ (MISO:Eu3+) phosphors exhibited a bright red luminescence peak at 612 nm, which is attributed to D-5(0)-> F-7(2) transition of Eu3+. The thermal quenching temperature of the optimum sample exceeded 480 K, which is much higher than the working temperature of light-emitting diode (423 K). The packaged white light-emitting diode (WLED) had CIE coordinates of (0.336, 0.340) with correlated color temperature of 5322 K and color rendering index value of 90. Furthermore, the latent fingerprints (LFPs) stained with MISO:Eu3+ phosphors were visualized with level 1-3 features, but their accuracy was relatively low. Therefore, oleic acid (OA) was utilized to form a hydrophobic coating on MISO:Eu3+ powders to improve fingerprint development, and the higher accuracy of level 1-3 features was achieved, especially level 3 features. The LFPs on smooth and rough surfaces stained with MISO:Eu3+@OA phosphors were easily collected at high contrast under 395 nm light. The obtained results prove that MISO:Eu3+ and MISO:Eu3+@OA can be considered as promising red phosphors for WLED and LFP identification and provide insight into the improvement of LFP development. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Phosphors with pure red emission were successfully prepared in this study, showing potential applications in LED lighting and fingerprint identification.