Influence of annealing temperature on persistent luminescence in BaAlO:Eu/Eu nanocrystals and its application for latent fingerprint detection.

The luminescent properties of europium (Eu) doped BaAlO phosphors were strongly influenced by post-annealing temperatures for blue-green persistent luminescence and latent fingerprints (LFPs). The X-ray powder diffraction patterns of the BaAlO: 1 mol% Eu nanophosphor, annealed between 1000 and 1300 °C, indicated a hexagonal ferroelectric phase. The X-ray photoelectron spectroscopy (XPS) revealed that the Ba atoms occupied two different sites in the BaAlO.

The role of thickness on the structural and luminescence properties of YO:Ho, Yb upconversion films.

The structural, surface, and upconversion (UC) luminescence properties of YO:Ho,Yb films grown by pulsed laser deposition, for different numbers of laser pulses, were studied. The crystallinity, surface, and UC luminescence properties of the thin films were found to be highly dependent on the number of laser pulses. The X-ray powder diffraction analysis revealed that YO:Ho,Yb films were formed in a cubic structure phase with an Ia space group.

High-contrast multi-surface imaging of latent fingerprints using color-tunable YOF:Tb,Eu ultrafine nanophosphors with high quantum yield.

Visualization of latent fingerprints (LFPs) using conventional powders has faced challenges on multicolor surfaces. However, these challenges are addressed by the advent of fluorescent powders in LFP detection, and they have redefined the effectiveness of the powder dusting method. In this study, color-tunable YOF:Tb,Eu nanophosphors were examined for LFP recognition and were evaluated for their practicality on different types of surfaces.