Composition design of low-melting point glass phosphors for red-light-emitting diode supported for colorblind people

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04759
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Suzuka National College of Technology
• Principal Investigator: Wada Noriyuki 鈴鹿工業高等専門学校, その他部局等, 教授 (30342504)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 発光ダイオード / 蛍光体 / 低融点 / ガラス / マンガン / 銅 / 銀 / アンチモン

Outline of Final Research Achievements

To realize red phosphor converted light emitting diode (red PCLED) having high brightness and broad emission suited for a color-blind parson, preparation of Mn2+-doped phosphate glasses co-doping with Cu+, Ag+, and Sb3+ ions having UV-excitable by a melt-quenching method was tried, and and their fluorescence spectral and softening properties were investigated. As a result, the concentration of Cu+, Ag+ ions, and Agn+ clusters (n = 2, 3) were controlled by melting temperature and time, their ions and clusters enabled to excite under UV light. In addition, Sb3+-co-doping enabled to be low melting temperature. From the above, it was successful to obtain Mn2+-doped phosphate glass with strong, broad, red fluorescence suited for red PCLED.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

色弱者の多くは，約620 nm以上の可視光線(赤色光)を視覚できないため，高輝度赤色の発光ダイオード(LED)(発光波長625 nm)を用いた赤信号や電光掲示板など公共の表示装置が視覚できない問題がある．本研究では，紫外励起下において高輝度でブロードな赤色蛍光を発現する低融点ガラスを作製することに成功した．このガラスを用いて励起光源の紫外LEDチップを被覆することで，健常者には赤色に，色弱者には橙色に見える高輝度かつブロードな赤色発光を有する赤色PCLEDが実現でき，上述の問題が解決される成果をえている．