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 SiO 2 @SrTiO 3 : Dy 3+ (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 SrTiO 3 . The photoluminescence emission spectra of SrTiO 3 :Dy 3+ (5 mol %) with different layers of SiO 2 coating display intense and characteristic peaks at ˜ 483 nm ( 4 F 9/2 → 6 H 15/2 ), 576 nm ( 4 F 9/2 → 6 H 13/2 ) and 664 nm ( 4 F 9/2 → 6 H 11/2 ). The broad thermoluminescence glow peak with maximum intensity at ˜ 200 °C for both with and without coated SrTiO 3 :Dy 3+ (5 mol %) nanopowders was noticed. The optimized SiO 2 @SrTiO 3 :Dy 3+ (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.