Controlled synthesis and photoluminescence behaviors of Lu2O3:Eu and Lu2O2S:Eu phosphor particles

Rounded Lu2O3:Eu phosphor powder with an average particle size of similar to 90 nm was synthesized via pyrolyzing the precipitation precursor prepared by a facile co-precipitation technique using ammonium hydrogen carbonate (AHC) as the precipitant, followed by direct sulfurization at 950 degrees C under a reducing atmosphere to yield twodimensional plate-like Lu2O3:Eu phosphor with a thickness of several micrometers. The photoluminescence (PL) behaviors of the two resultant phosphor powders were systematically investigated. The oxide and oxysulfide phosphors displayed characteristic red-light emissions of Eu3+ at similar to 612 and 630 nm, respectively, which were derived from D-5(0).(1)-> F-7(J)(J = 0, 1, 2, 3) transitions of Eu3+ . The luminescence quenching types of both phosphors were dominated by exchange interactions and the optimum Eu3+ concentrations were found to be similar to 2.5 at.% for Lu2O3:Eu and similar to 1.0 at.% for Lu2O3:Eu. The oxysulfide phosphor had a PL intensity similar to 3.5 times stronger than the oxide powder. The Lu2O3:Eu and Lu2O3:Eu phosphors had CIE color coordinates of (0.65, 0.35) and (0.61, 0.39), which fall into the categories of reddish-orange and orange colors, respectively. A shorter fluorescence lifetime (similar to 602.9 ps) and a higher percentage of excitation absorption 71%) were observed for the oxysulfide relative to those of the oxide (similar to 2.4 ms and eta approximate to 35%).