Areas of Research
Our research interests cover a broad range of cutting-edge materials science projects. One of our major interests has been to thoroughly characterize optical materials (single crystals, ceramics, nanocrystals, glasses, polymers) doped with rare earth (RE) and evaluate their potential for various photonic applications. As the nanotechnology field is fast emerging and its applications are expected to be limitless, we are currently involved in the synthesis, characterization and application of various nanoparticles of RE ions doped in multitude of hosts, noble metals, and their conjugates. Our goals are to understand the fundamental physics of these nanoparticles, their optical and magnetic properties, their structural effects - such as size, surfaces, interfaces, etc. - with the ultimate goal of applying them as laser materials, optical fibers, planar waveguides, security authentication, pigments, fluorescence labeling, scintillators, lighting, bio-imaging, bio-sensors, cancer therapy, and optical displays.
SEM images of (a) star-shaped RE-doped phorphor particles and (b) close-up view
HAADF STEM Z-contrast image of GdF3:Nd3+ nanocrystals
Emission comparison between the most efficient single dopant (Nd3+ 0.5%) in black and double dopant (Nd3+ 10% and Yb3+ 4%) in red. A 71.5% increase was achieved by simply introducing Yb3+ into the system and carefully doping Nd3+. The inset shows the emission intensity of Nd3+ and Yb3+ doped nanoparticless as a function of Nd3+ concentration.
(a) Magnetization curve of GdF3:Nd3+ nanoparticles. The inset of (a) shows the particles attracted to a magnet as a demonstration of the magnetic nature of the nanoparticles. (b) GdF3:Nd3+ nanophosphors are in deionized water with the original opaque colloidal suspension at 0 hours and an almost transparent suspension after 20 hours with magnet on one side (0.2 T) that shows that most of the nanophosphors are attracted by the magnet as seen through the upper transparent part of the suspension.