Optimized Tb3+-activated highly efficient green-emanating BaLa2ZnO5 nanophosphors in PDMS matrix for flexible display, anti-counterfeiting, and dermatoglyphics applications

Abstract

Green-emitting BaLa2ZnO5:Tb3+ nanophosphors (NPs) were synthesized via a safe and cost-effective solution combustion process, with Tb3+ dopant content optimized at 4 mol% to avoid concentration quenching. The NPs exhibited strong green emission at 545 nm, a decay lifetime of 0.520 ms, and a quantum efficiency of 35.12%. Chromaticity generalization demonstrated their potential for advanced lighting devices, with coordinate values of (0.2669, 0.5274), a temperature of 7246 K, and color purity of 91.03%. The optimized NPs produced a proof-of-concept security ink and a translucent anti-counterfeiting (AC) film that could emit a powerful green light when exposed to UV light. A Python program was developed to enhance and extract features from fingerprints, emphasizing the importance of each step in producing a perfectly improved image. The minutiae FPs were color-coded to indicate bifurcation and termination, and the final stage of thinning and binarizing images revealed Level-I and Level-II features. The optimized BLZO:4Tb3+ NPs demonstrated great potential for solid-state lighting, flexible displays, anti-counterfeiting, and dermatoglyphics applications.