Phosphor preparation

P-22 ZnS Ag+ + ZnCdS2 Ag+ + Y202S Eu3+ Mix of phosphors, each phosphor prepared and applied separately. ZnS, (Zno.88-Ago.i2)S2> MgCl2 LiS04 ZnS, (Zn0.715.Ag0.285)S2, CdS MgCl2.NaCl Y203 Euo.65 S Color television (blue, green, and red emitters)... 

GEMINAL ACYLATION-ALKYLATION AT A CARBONYL CENTER USING DIETHYL N-BEN ZYLIDENEANINOfCTHYL PHOSPHORATE PREPARATION OF 2-HETHYL-2-PHENYL-4-PENTEHAL (4-Pentenal, 2-i ethyl-2-phenyl-)... 

The compounds of groups IIB-IVB are often prepared in poiycrystaliine form as phosphors, catalysts (15.2.2.2) and infrared transmitting materials. Their use as semiconductors is almost exclusively for optoelectronic purposes (i.e., light emission and detection). Thus the phosphor preparation technology has relevance to preparation of these semiconductors in powder form. The most common reactions employed are... 

Before we begin a discussion of nucleation dturing a precipitation, we need to explain some of the intricacies of precipitation. We first start with two solutions, one containing the cation of interest and the other the anion. Both involve soluble substances like nitrates or chlorides for the cations and acids or sodium compounds (or the like) for the anions. When the two solutions are combined, a precipitate will form if its aqueous solubility, as defined by its solubility product, is less than either of the cation and/or anion solubilities. What this means is that if we use two soluble solutions and combine them, a precipitate will form if it is insoluble in the aqueous solution. There are many examples of precipitate formation. We need to define the effect of exactly how the precipitation should be carried out in terms of phosphor preparation. 

Phosphor preparation parameters can be divided into two (2) classes, independent and dependent variables. 

The following lists the independent variables of phosphor preparation ... 

In contrast, Ba2Si04 works better with Sn2+. The exact reason for this is not known, but it is suspected that the phonon spectrum of the host and/or the crystal structure is the answer. This brings us to another major rule in phosphor preparation, namely ... 

This brings us to another rule for phosphor preparation, namely-... 

List of Lithium-Based Low Z Phosphors Prepared during the Research Work... 

Jung KY, Lee HW (2007) Enhanced luminescent properties of Y3Al50i2 Tb, Ce " phosphor prepared by spray pyrolysis. J Lumin 126 469-474... 

He H, Fu RL, Wang H, Song X, Pan Z, Zhao X, Zhang X, Cao Y (2008) Li2SrSi04 Eu phosphor prepared by the pechini method and its apphcation in white light emitting diode. 

Fan L, Zhao X, Zhang S, Ding Y, Li Z, Zou Z (2013) Enhanced luminescence intensity of Sr3B20g Eu phosphor prepared by sol-gel method. J Alloys Compd 579 432-437... 

Zhang Z, Feng J, Huang Z (2010) Synthesis and characterization of BaMgAlioOi7 Eu phosphor prepared by homogeneous precipitation. Particuology 8 473-476... 

Zhao CL, Hu YS, Zhuang WD, Huang XW, He T (2009) Lumineseence modification of Eu -activated molybdate phosphor prepared via co-precipitation. J Rare Earths 27 758... 

The nitride phosphors prepared by the CRN method always contain some amount of residual carbon, which significandy decreases the absorption and luminescence of the phosphor powder itself. Therefore, it is necessary to remove the excess carbon after the carbothermal-reduction process. The common way for the removal of carbon is to fire the powder in an oxidizing atmosphere at temperatures >600 °C. However, this process may also lead to the oxidation of the phosphor powders, which decreases the luminescence of phosphors. 

Nitridosilicate phosphors prepared by the ammonothermal synthesis method exhibit high phase purify and fine particle size. 

The synthesized CaAlSiN3 Eu powder consisted of irregular particles with a particle size of 6-9 pm, which is larger than that prepared by the solid-state reaction. The luminescence intensity of the phosphor prepared by the direct nitridation was comparable with that prepared by the solid-state reaction. 

Li H-L, Xie R-J, Zhou G-H, Hirosaki N, Sun Z (2010) A cyan-emitting BaSivNio Eu " phosphor prepared by gas reduction and nitridation for UV-pumping white LEDs. J Electrochem Soc 157(7) J251-J255... 

C Xu, A Watkins, RE Sievers, X Jing, P Trowga, CS Gibbons, A VechL Submicronsized spherical yttrium oxide based phosphors prepared by supercritical CO2-assisted aerosotization and pyrolysis. Appl Phys Lett 1997 12 1643. 

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