CFN Special Seminar

Rare-earth (RE) ions play a significant role as the active centers in modern optical technology. The luminescent properties of rare-earth doped materials have attracted great attention for a wide variety of applications including phosphors, lasers, and scintillators. This talk will cover the overview of the spectroscopic evaluation of the following research areas in the UV-Visible (displays, scintillators), Near-IR, and Mid-IR (infrared solid-state laser sources) spectral region using laser-induced fluorescence spectroscopy. The development of RE-activated nitride semiconductor based electroluminescent devices (thin films, nanomaterials) has been of great interest for several optoelectronic applications (e.g. LED's, lasers). Results of photoluminescence properties of RE-doped GaN powders prepared by a Na-flux method will be presented. The development of novel infrared fluorescent materials continues to be of interest for applications in solid-state gain media, infrared sensing, optical taggants, and optical cooling. RE doped crystals with low maximum phonon energies have shown efficient near-IR and mid-IR emissions as well as lasing at room temperature. PbCl2 and PbBr2 based ternary lead halides (e.g. KPb2Cl5, RbPb2Cl5, KPb2Br5, RbPb2Br5) materials have recently emerged as new non-hygroscopic laser hosts with low maximum phonon energies (~138-203 cm-1), which lead to small non-radiative decay rates for trivalent rare earth dopants. In addition, pure and RE activated halide crystals were also investigated to develop efficient scintillators. In this talk, the material synthesis, purification, crystal growth, and spectroscopic characterization of rare-earth activated optical materials will be presented for possible applications in displays, optical cooling, infrared lasers and radiation detectors.