Open AccessFluorescence enhancement mechanism in phosphor CaAl 12 O 19 :Mn 4 + modified with alkali‐chloride
Author(s) -
Li Yanan,
Xiao Zunhong,
Xu Lizhi,
Zou Yingping,
Guo Mingchun
Publication year - 2013
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2012.0809
Subject(s) - alkali metal , phosphor , luminescence , chloride , ion , alkaline earth metal , inorganic chemistry , analytical chemistry (journal) , fluorescence , doping , chemistry , photoluminescence , ionic radius , materials science , optics , physics , optoelectronics , organic chemistry , chromatography
CaMAl 12 − x O 19 : x Mn 4 + (M is one or more of K + , Na + , Li + ) materials were prepared by a combustion method in air atmosphere. The Mn concentration, the influence of one or more alkali‐chloride on luminescence properties, crystal phases and surface morphology of the samples were investigated. The fluorescence intensity of CaAl 11.98 O 19 :0.02Mn 4 + modified by combining three kinds of alkali‐chloride can be enhanced by three times. Blue shift of CaMAl 12 − x O 19 : x Mn 4 + luminescence is explained from the point of view of enhancing electron cloud deformation after doping. Alkali metal ions were beneficial to form hexagonal CaAl 12 O 19 while there was certain inhibition to other peak strengths. The mechanism is the coexistence of alkali‐chloride replacing Al 3 + or Ca 2 + instead of Mn 2 + based on the difference of cation radius, this would increase the luminous centre of Mn 4 + and provide charge compensation at the same time. The size of red phosphors was 5–10 μm, which is useful for light emitting diode applications.