Structural and luminescence properties of undoped, Nd3+ and Er3+ doped TiO2 nanoparticles synthesized by flame spray pyrolysis method

Bulk and thin film forms of titanium dioxide (TiO2) have been studied many times due to its very promising optical properties. In this study, low-cost flame spray pyrolysis (FSP) synthesis of Nd3+/Er3+doped TiO2 nanoparticles has been reported for the first time. The produced particles were post-annealed after FSP process at 550 °C in order to obtain crystalline structure. The phase and elemental analysis of the produced materials were performed by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS), respectively. The surface morphology, accurate size and specific surface area of the primary particles were identified using scanning electron microscopy (SEM) and particle size analyser. Luminescent properties of the produced nanoparticles were investigated by steady state and time resolved fluorescence spectra. Doping of TiO2 nanoparticles with the rare earths of Nd3+and Er3+resulted in visible and near-infrared light emission when excited at 364 nm. The utilized nanoparticles yielded bi-and tri-exponential decay curves. Additionally, they exhibited typical upconversion luminescence when radiated by 810 nm.