发光二极体激发之SrSi2N2O2 Yb.pdf

LED 固態照明 專題 發光二極體激發之SrSi N O :Yb 化 2 2 2 合物螢光粉介紹 An Introduction of SrSi N O :Yb Phosphors for 2 2 2 Light Emitting Diodes 劉如熹、劉宇桓 Ru-Shi Liu, Yu-Huan Liu 1996 年日本日亞化學公司以藍光晶片搭配黃色釔鋁石榴石型螢光粉而發展白光發光二極體， 開啟發光二極體邁入照明市場之序幕。雖此法製造白光發光之效率佳，然其光色色溫高、演 色性差，且有氧化物螢光材料於高溫下熱衰竭等缺點。本文提出以氧氮化合物為主體結構之 螢光粉(SrSi N O :Yb) 。此氧氮化合物因具較純氧化物強之共價性，故於高溫穩定性較佳， 2 2 2 並利用光激發光光譜儀(photoluminescence, PL) 分析螢光粉之激發光譜與放射光譜特性。 The first white LED, commercialized in 1996, is composed of a blue LED and a yellow phosphor layer, namely, yttrium aluminum garnet (YAG). The color rendering index (Ra) of the YAG-based LED is about 80, which is enough for general illumination. However, it is not suitable for certain medical applications and architectural lighting purposes due to the poor performance of red component in the spectra. Moreover, the YAG phosphor has the disadvantage of thermal quenching at high temperature. In this study, we concentrate on SrSi N O :Yb phosphors among the oxynitride 2 2 2 compounds, which are nontoxic and stable under high temperature. Besides, photoluminescence (PL) and the CIE chromaticity coordinates were obtained to show emission properties. 研製生產出第一顆實用之紅光發光二極體後，其後 一、前言 隨金屬有機化學氣相沉積法(metal organic chemical 發光二極體 (light emitting diode, LED) 乃由半 vapor deposition; MOCVD) 技術逐漸成熟，於 1991 導體材料所製成之發光元件，元件具兩個電極端 年美國HP 公司與日本東芝研發以AlGaInP 為基材 子，於端子間施加電壓，通入極小之電流，經由電 之綠光發光二極體。直至1993 年日本日亞(Nichia) 子電洞之結合，可將剩餘能量以光之形式激發釋 化學公司才發展出氮化鎵 (GaN) 發光二極體，突 出。不同之半導體基材因而引發不同波長之發光二