Nanostructures for WLEDs and provides authentication for latent fingerprints visualization under diverse environmental conditions

Abstract

SnO2:Eu3+ nanopowders prepared by bio-friendly hydrothermal method using Aloe Vera gel as a bio-template. Prepared samples were characterized for their structural, morphological and purity using powder x-ray diffraction, scanning/transmission electron microscopies and diffused reflectance spectroscopy. Morphology shows the layered structures with sharp edges confirmed makes the system with better surface area along with sticky nature. Energy band gap of the samples varies from 3.44 to 3.74 eV. Photoluminescence results showed the dipolar-dipolar interactions and leading to white light emission when excited with 392 nm excitation wavelength. Optimized compounds were explored for their feasibility to visualize well-preserved latent fingerprints on various types of surfaces. Visualized fingerprints show the details of third-level ridges, bifurcations and pores with high selectivity, better contrast and without background hindrance. Clarity of developed fingerprints was also examined under aquatic environment and abrasion test. Even in severe environmental conditions demonstrated successfully the robustness and supremacy of the present approach. It is anticipated that the present nanostructures could be used in the visualization of LFTs and its utility for various forensic and optoelectronic applications.