Thermal degradation and its mechanism of nitride phosphors for white light-emitting diodes

2014 Fiscal Year Final Research Report

• Project/Area Number: 23560811
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: National Institute for Materials Science
• Principal Investigator: XIE RONGJUN 独立行政法人物質・材料研究機構, サイアロンユニット, 主席研究員 (00370297)
• Co-Investigator(Kenkyū-buntansha): NISHIMURA Toshiyuki 独立行政法人物質・材料研究機構, サイアロングループ, 主席研究員 (50354428)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 窒化物蛍光体 / 熱劣化 / 白色LED / 微構造 / 表面改質

Outline of Final Research Achievements

Thermal stability and its enhancement of a variety of nitride phosphors for solid state lighting were investigated in this project. The thermal stability of nitride phosphors is strongly correlated with the crystal structure, bandgap structure and the surface state, so that the thermal stability of nitride phosphors can be significantly enhanced by the surface coating, passive oxidation, or bandgap engineering. In addition, the thermal degradation mechanism was clarified by conducting the aging test of nitride phosphors at high temperature in air, which was caused by the oxidation of both activators and host crystals. Therefore, in order to prevent the phosphors from oxidation the composition and surface modification of phosphors need to be considered carefully.

Free Research Field

工学