文档介绍：摘 要
白光二极管(WLED)技术以其节能,环保和长寿命等优点成为各国竞争的高新技术之一。为了发展新一代功率型(瓦级)、高亮度(>1 001m)、高显色指数(>80)白光。现有的蓝光激发下的掺铈离子的钇铝石榴石(YAG:Ce”)、近紫外或蓝紫光激发下的宽激发带硅酸盐基质白光发射的荧光体材料是一个重要的创新途径。
研究了一种蓝光发射特性的新一代稀土硅酸盐基质白光荧光体,获得如下创新结果:
(1)采用一种多组分的复合溶胶技术制得物相很纯的硅酸盐基质荧光体。实测的激发光谱峰值的典型波长在350-470nm的较宽范围,取得了宽激发带波长范围的积极研究结果。用波长为470nm的蓝光激发,发射波长峰值为 (橙黄光)。
(2)获得了正硅酸盐体系碱土元素为基荧光体的微结构和荧光光谱的关系。用Ui teret关系,得到Eu2+离子的5d激发带边位置(或5d-4f发射高能峰位置)与阳离子配位数为6的对应关系,获得了Sr。Ca:.。SiO。、Sr。Mg:一。SiO。和 Sr。Ba。一。SiO。体荧光体的颗粒的XRD、形貌以及吸收、激发和发射光谱性质。
(3)对复合溶胶的气溶胶技术,重点考察了化学计量比、溶胶规律、烧结温度等,获得了一系列完整的基于微结构一光谱的可控技术参数。
(4)荧光体颗粒为一种纳米颗粒的自组装集合体,疏松,平均粒径在几微米,不用球磨,从而避免了球磨对荧光体晶格的破坏导致的荧光体发光亮度大幅降低的问题。
(5)测试了荧光体的激发一发射光谱的化学稳定性和热稳定性。关键词:白光LED,气溶胶技术,硅酸盐基质,宽激发带
Abstract
White LEDs(WLEDs)has e one of the key hi-technology world
Wide due to its attractive advantages of energy consumption saving, environmental and lifetime long—lasting YAG:Cej+phosphor puimped with chip blue light needs innovation to improve the these,the silicate host phosphors with UV'nUV or blue—UV lights in wider excitation wavelength range for white-emitting is one of the innovative petitive
approaches.
With the aim to the problems mentioned above,we investigated a new
rare earth doped silicate base relationship between preparation, microstructure and luminescent properties presented experimentally and theoretically in important results we obtained are described as follows:
spray-pyrolysis procedure was employed to prepare phase-pure rare—earth doped silicate base measured wavelengths of these phosphors
range from 350nm to typical emission wavelength lies at 567nm upon exited by 470nm light.
relationships between microstructure and luminescent properties of these silicate base phosphors are primarily lower energy edge location of Eu2+ion is found to correspond to a six—coordinated number by using Uiteret formula. Furthermore,the XRD ptterns,morphologies and spectra of