Dissertation > Excellent graduate degree dissertation topics show

Study on Surface Modification of YAG:Ce3+ Phosphor Powder Using for LED

Author: YangZuo
Tutor: QiuKeHui
School: Chengdu University of Technology
Course: Mineral materials science
Keywords: YAG:Ce3+ Phosphor powder SiO2 thin film sol method fluorescence properties thermal degradation
CLC: TM923.04
Type: Master's thesis
Year: 2011
Downloads: 139
Quote: 0
Read: Download Dissertation

Abstract


Surface modification can be done by certain methods in order to improve the physical or chemical properties of the surface of the powder, such as surface structure, surface energy, surface wettability, electrical property, adsorbability and so on. This modification can fulfil the needs of development of new material and technology in modern society.Phosphor is one of the key material in the LED device. Its properties directly affect the brightness, chromaticity coordinates, chromatic temperature, color rendering property and so on. Uncoated phosphor powders are agglomerate and not stable in electrical and chemical properties because of extrinsic and intrinsic factors. This can lead to low temperature of fluorescence quenching, nonhomogeneity in luminescence and so no. So it is necessary to find a new method to improve the stability of the phosphor. Surface coating is an good method, which can improve the agglomeration, corrosion resistance and thermal degradation properties of powders through coating a layer of thin film. That even can improve the intension and tenaciousness of powder.In this paper,the modification of YAG:Ce3+ phosphor powders were studied by the surface coating technology to solve the problem of thermal degradation during the using of LED. The silicon dioxide was chose as coating material according to its excellent physical and chemical properties. The sol method was used to coat the YAG:Ce3+ phosphor with TEOS as silicon reagent. The influence of coating time, coating temperature, pH of the catalyst, sintering temperature and time, and the amount of SiO2 to the effect of coating was studied. The phase composition, microstructure and luminescence properties of the powders coated were characterized by SEM, XRD, TEM and FS. The XRD analysis showed that crystal phase composition after coating is the same with that uncoated powders. The process did not introduce other component. The TEM images indicated that a compact homogeneous film which was confirmed as SiO2 film by energy spectrum analysis was coated on the surface of YAG:Ce3+ phosphor particles successfully. And the fluorescence spectrum showed that not only the luminescence properties of the YAG:Ce3+ phosphor was not affected by the film, but also the thermal degradation property was improved obviously by the coating process.

Related Dissertations

  1. Flexible,rigid,Synthesis and characterization of mixed ligand complexes,O621.1
  2. The Research on Sulfate Leaching Properties of Cation-exchange Resin Used in Power Plants,TQ425.23
  3. Thermal degradation and combustion characteristics of marine biomass fiber Retarding Mechanism,TQ352.1
  4. Study on the Property and Process of Low Voltage ZnO Varistors,TM54
  5. Process optimization and stability studies clarified juice,TS255.44
  6. Thermal Degradation, Flame Retardant Properties of Polycarbonate/Polyhedral Oligomeric Silsesquioxane Composites,TB33
  7. Preparation of dimethylaminopropyl methacrylamide , quaternized with AMPS copolymer,TQ316.3
  8. Aromatic heterocyclic skeleton Dehydroabietate Construction and Fluorescence Properties,O621.2
  9. Carbomagnesiation of Acetylenic Sulfones and Its Applications in the Synthesis of Polysubstituted Alkenes,O621.25
  10. Solution-based Route to Low Dimensional Organic-Inorganic Lanthanide Hybrid Structure: Synthesis, Characterization and Their Properties,TB34
  11. The pyridin porphyrin -5 - fluorouracil in the synthesis of the compounds of,TQ464
  12. Study on Preparation and Luminescence of Green Phosphate Phosphor,O482.31
  13. Studies on the Xanthone-crown Ether and Their Rare-earth Complexes,O641.4
  14. Study on Preparation and Properties of K0.5Na0.5NbO3 Ceramic Films,TQ174.6
  15. Schiff base complexes as building blocks acid -based metal -organic frameworks control assembly,O621.1
  16. Amide -type multi-legged body Rare supramolecular complexes,O627.3
  17. 8 - hydroxyquinoline quinoline skeleton Cu ~ 2 / Ag ~ Synthesis , Structure and Fluorescence Properties of,O621.13
  18. Based on 1,3 - adamantane acid coordination polymers constructed and its properties,O631.3
  19. Preparation and Propertities of Gold/Silver Low-dimensional Nanomaterials and Their Composites,TB383.1
  20. Synthesis, characterization and fluorescence -tert-butyl-calix [6] arene Rare Earth Complexes,O627.3
  21. New monosubstituted β- diketone pyridine derivatives and Its Rare Earth Complexes Synthesis, Characterization and Fluorescence Properties of,O627.3

CLC: > Industrial Technology > Electrotechnical > Electrification,electrical energy application > Electrical lighting > General issues > Filament material
© 2012 www.DissertationTopic.Net  Mobile