The luminescent properties and latent fingerprint identification application of AlN:Ce, Tb phosphors

Ce³⁺and Tb³⁺ion co-doped aluminum nitride (AlN) phosphors were prepared by a simple solid-state reaction. X-ray diffraction (XRD), high resolution transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), as well as photoluminescence (PL) spectra were employed to analyze the samples. The crystal structure, morphology, photoluminescence properties and the energy transfer process of Ce³⁺and Tb³⁺ion co-doped AlN phosphors were carefully investigated. An enhanced light emission and red-shifted excitation wavelength can be observed in AlN:Tb phosphors after co-doped with Ce³⁺ion. The results indicate that the Ce³⁺and Tb³⁺ion co-doped AlN phosphors can be effectively used in fingerprint identification. The phosphor-marked fingerprints on various substrates can be clearly manifested with good contrast and weak background inference, holding significant applications in the forensic field.