Hydrothermally synthesized Dy³⁺ doped SrZrO₃ nanophosphors for efficient white light emission and latent fingerprint detection

Abstract

Environmental safety and energy conservation have emerged as the two most crucial fields in the past few years. This paper reports, the simple hydrothermal approach used to prepare Dy 3 + ions (1–9 mol%) incorporated SrZrO 3 nanopowders (NPs). A thorough investigation was conducted into the usage of prepared particles for lighting applications. Structure of SrZrO 3 was evaluated from the powder X-ray diffraction (PXRD) patterns. Band gap values were evaluated by using diffuse reflectance spectra (DRS) and noticed between 4.40 and 4.95 eV. The stretching and bending vibrations of the synthesized samples were studied by using Fourier infrared Spectroscopy (FTIR). The metal-oxygen bonds Zr-O and Sr-O observed between 500 and 800–1600 cm −1 wavenumber. In the scanning electron microscope (SEM) micrographs, flower-like hierarchical structures were observed with different sizes ranging between 37 and 70 nm. The formation of these structures was studied by means of Ostwald’s-ripening process. The photoluminescence (PL) emission spectra was recorded by monitoring 386 nm excitation. The distinctive profiles of Dy 3+ ions centred at 482, 574 and 636 nm were observed and ascribed to 3 F 9/6 → 6 H 15/2 , 3 F 9/6 → 6 H 13/2 and 3 F 9/6 → 6 H 11/2 transition respectively. The PL intensity increases up to 5 mol% of Dy 3+ ions and there after it decreases owing to concentration quenching process. The white colour emission was evaluated by chromaticity diagrams. The chromaticity color diagrams indicate the pure white color emission under NUV excitation (386 nm) wavelength. The optimized powders were also checked for their applicability in the forensic field. Latent fingerprints (LFPs) on various substrate surfaces were evaluated by using the synthesized powders. The LFPs showed all the 3 types of ridge details such as loop, ridge end, fork, island, hook and sweat pores. Present powders were effective in the fabrication of wLEDs and advanced forensic applications.