Influence of surface modification on enhancement of luminescent properties of SiO2@SrTiO3:Dy3+ nanopowders: Probe for visualization of sweat pores present in latent fingerprints

Abstract

The paper reports, novel SiO2@SrTiO3: Dy3+ (5 mol %) nanopowders fabricated via the low temperature sonochemical route by utilizing bio-surfactant Aloe Vera gel extract. The powder X-ray diffraction results display intense and narrow peaks confirm the monoclinic phase of SrTiO3. The photoluminescence emission spectra of SrTiO3:Dy3+ (5 mol %) with different layers of SiO2 coating display intense and characteristic peaks at ~ 483 nm (4F9/2 → 6H15/2), 576 nm (4F9/2 → 6H13/2) and 664 nm (4F9/2 → 6H11/2). The broad thermoluminescence glow peak with maximum intensity at ~ 200 oC for both with and without coated SrTiO3:Dy3+ (5 mol %) nanopowders was noticed. The optimized SiO2@SrTiO3:Dy3+ (5 mol %) nanopowders was most suitable for visualization of the latent fingerprints, revealing explicit specific ridge characteristics, including level I -III. Therefore, the present work opens a new possibility of use of prepared nanopowders for WLEDs, visualization of latent fingerprints and dosimetry applications.