Fluorescence enhancement mechanism in phosphor CaAl12O19:Mn4 + modified with alkali‐chloride. (1st May 2013)

• Record Type: Journal Article
• Authors: Li, Yanan; Xiao, Zunhong; Xu, Lizhi; Zou, Yingping; Guo, Mingchun
• Is Part Of: Micro & nano letters. Volume 8:Number 5(2013)
• Page Start: 254
• Page End: 257
• Publication Date: 2013-05-01
• Subjects: calcium compounds -- charge compensation -- combustion synthesis -- doping profiles -- fluorescence -- lithium compounds -- manganese -- phosphors -- potassium compounds -- sodium compounds -- spectral line shift -- surface morphology; fluorescence enhancement mechanism -- alkali‐chlorides -- material preparation -- combustion method -- air atmosphere -- Mn concentration -- luminescence properties -- crystal phases -- surface morphology -- fluorescence intensity -- blue shift -- electron cloud deformation -- doping -- alkali metal ions -- hexagonal phase -- cation radius difference -- luminous centre -- charge compensation -- red phosphor size -- light emitting diode applications -- CaKAl12‐xO19Mn4+ -- CaNaAl12‐xO19Mn4+ -- CaLiAl12‐xO19Mn4+; Nanotechnology -- Periodicals; Nanostructures -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1049/mnl.2012.0809
• Languages: English
• ISSNs: 1750-0443

Abstract

Abstract : CaMAl12 − x O19 : 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 CaAl11.98 O19 :0.02Mn 4 + modified by combining three kinds of alkali‐chloride can be enhanced by three times. Blue shift of CaMAl12 − x O19 : 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 CaAl12 O19 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.