Open AccessParticle-swarm-optimization-assisted rate equation modeling of the two-peak emission behavior of non-stoichiometric CaAl_xSi_(7-3x)/4N_3:Eu^2+ phosphors
Author(s) -
Yoon Won Jung,
Bong-Hyun Lee,
Satendra Pal Singh,
KeeSun Sohn
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.017805
Subject(s) - phosphor , activator (genetics) , stoichiometry , materials science , analytical chemistry (journal) , gaussian , emission spectrum , spectral line , mineralogy , chemistry , physics , optoelectronics , chromatography , biochemistry , computational chemistry , astronomy , gene
We examined non-stoichiometric CaAl(x)Si((7-3x)/4)N(3):Eu(2+) phosphors that were intentionally prepared with x = 0.7-1.3 to identify the origin of the deconvoluted Gaussian components that constitute the emission spectra of stoichiometric CaAlSiN(3):Eu(2+) phosphors. The Al/Si molar ratio around the Eu(2+) activator caused the deconvoluted Gaussian peaks. The Eu(2+) activator sites in Al-rich environments gave rise to the lower-energy emission peak, while those in Si-rich environments were related to the higher-energy emission peaks. Active energy transfer from the Eu(2+) activator site in the Si-rich environment to the Eu(2+) activator site in the Al-rich environment was confirmed. Particle swarm optimization was employed to estimate the nine unknown decision parameters that control the energy transfer process. All of the decision parameters were estimated within the range of reasonable values.