Cathodoluminescence study of novel sol–gel derived Y3−xAl5O12:Tbx phosphors

Autor: David C. Morton, K. W. Kirchner, Steven Blomquist, D. Ravichandran, Jae Young Choe, Eric Forsythe
Rok vydání: 2001
Předmět:
Zdroj: Journal of Luminescence. 93:119-128
ISSN: 0022-2313
DOI: 10.1016/s0022-2313(01)00178-8
Popis: The synthesis, physical characterization and cathodoluminescence (CL) of sol–gel derived Y 3− x Al 5 O 12 : Tb x 3+ (YAG, x =0.03–0.15) powders is presented. Metal–alkoxide organic precursors were used as the starting materials to form the sol–gel with the required stoichiometry. At a temperature between 900 and 950°C the non-crystalline xero–gel fully crystallized to form the single-phase YAG powder. The powder X-ray diffraction showed that the garnet structure and all reflections were indexed without any other secondary impurity phases. From the CL spectrum, all possible transitions 5 D 4 → 7 F 1…6 due to Tb 3+ in YAG structure were identified including the bright green emission at 548 nm. The highest luminance at a fixed beam current density was observed for the Tb concentration of x =0.12 (4% atomic). The CL intensity increased linearly with current densities from 1 to 60 μA/cm 2 but remained nearly constant from 60 to 100 μA/cm 2 . Two exponentially decaying functions that were fitted to the pulsed-CL decay curve illustrated the emission decay from 5 D 4 and 5 D 3 to 7 F J levels with their characteristic lifetimes. Both CL luminance and the decay time are comparable with commercially available optimized phosphors used for CRT and FED applications.
Databáze: OpenAIRE
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