Cutting-edge applications of oleic acid-modified CdSiO3: Ce3+ phosphors: Artificial intelligence enhanced latent fingerprint detection, anti-counterfeiting and optical thermometry

Abstract

A series of (1–11 mol%) Ce³⁺ doped CdSiO₃ phosphors are synthesized via a solution combustion method, and the sample with the optimal doping concentration underwent surface modification with oleic acid (OA). X-ray diffraction (XRD) analysis confirmed the formation of high-purity, well-crystallized CdSiO₃:Ce³⁺ phosphors. Upon 347 nm UV excitation, the phosphor exhibited intense blue emission at 400 nm, with an optimized Ce³⁺ concentration of 5 mol%, attributed to dipole-dipole interactions. The OA-modified phosphor demonstrated significantly enhanced properties, achieving a color purity (CP) of 97.2% and Internal quantum efficiency (I_QE) of 82.5%. The phosphor also exhibited excellent thermal stability, retaining 93.0% of its emission intensity at 423 K and a thermal quenching temperature exceeding 483 K, with a high activation energy (Eₐ) of 0.384 eV. In practical applications, the OA modified phosphor showed exceptional performance in latent fingerprints (LFPs) detection and anti-counterfeiting (AC) across different substrates, offering high resolution, contrast, and minimal background interference. MATLAB based analysis yielded a matching score of 94.52%, surpassing conventional benchmarks, underscoring the phosphor's potential for advanced fingerprint identification. These results demonstrate that the CdSiO₃:5Ce³⁺ phosphor is a promising candidate for applications in white light-emitting diodes (w-LEDs), optical thermometry, forensic analysis and AC technologies.