Tailored auto-combustion synthesis and optical and structural characterization of TiO2:Dy3+(1–11 mol%) nanostructures for wLED and latent finger print applications

Abstract

Un-doped and dysprosium (Dy3+) doped (1–11 mol%) titanium dioxide (TiO2) nanoparticles (NPs) were synthesized by low temperature solution combustion route. The structural, morphological and nanostructural characterization of NPs were performed by powder x-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis, respectively. Rarely found rutile to anatase phase transition was observed by Dy3+ doping in TiO2 NPs using PXRD. The energy gap (Eg) of un-doped and Dy3+ doped TiO2 NPs were estimated by diffused reflectance spectra (DRS) between 2.92 and 3.07 eV. The active vibrational Raman modes of pure TiO2 were observed at 141, 446 and 608 cm−1. The mode alleged at 229 cm−1 indicates the rutile phase of TiO2 caused by second order effect. Studies of CIE and CCT confirmed that the NPs may be used in wLED applications. A rise of asymmetry ratio from 1.326 to 1.3453 with dopant concentration was observed in the photoluminescence (PL) spectra. The optimized TiO2:Dy3+ (9 mol%) nanostructures were used for the visualization of latent finger prints (LFPs) on porous and non-porous surfaces from level I to level III of ridge features.