白光LED用高配位钨钼酸盐体系红色荧光粉的制备与发光性能研究
发布时间：2019-06-12 17:35
【摘要】：白光发光二极管(LED)具有节能环保、寿命长、响应速度快、体积小可进行平面封装等诸多优点,被公认为第四代照明光源。目前,白光LED的实现方案主要以荧光转换型为主,然而,目前红粉效率低,且不稳定,限制了高显色指数、高效率白光LED的发展,因此,研究近紫外光芯片适用的高效红粉变的非常重要。本学位论文主要研究近紫外光芯片用红色荧光粉,采用一种简单的溶胶-凝胶法制备了Sr2MgWO6:Eu、Sr2CaMO6:Eu、Sr3WO6:Eu三种体系红色荧光粉。(1)实验研究了Sr2MgWO6:Eu体系红色荧光粉的荧光性能,研究了激活剂浓度与发光性能的关系、Sm3+离子的引入对发光性能的影响以及电荷补偿对发光性能的影响。实验结果表明,激活剂浓度在x=0.1时,Sr2-2xMgWO6:2xEu的荧光性能最佳;Sm3+离子在Sr2MgWO6:Eu体系中可以起到优质敏化剂的作用,Sm3+离子的引入可以拓宽近紫外区的激发光谱,并且能明显的提高发射强度,而且并未发现来自Sm3+的特征发射光谱;采用Li+做电荷补偿效果最好,发射强度约为不做电荷补偿的7倍,并且色纯最高为98.4%,色坐标为(0.66,0.33),非常接近NTSC标准值(0.67,0.33)。此外,Sr2MgWO6:Eu体系红色荧光粉在465nm光激发下的发射强度更大,说明该体系荧光粉也适合应用在蓝光芯片上。(2)实验研究了Sr2CaMO6:Eu体系荧光粉的荧光性能,其激发光谱与近紫外光芯片有极佳的匹配,电荷迁移带覆盖近紫外光区域,峰值位于~400nm处。实验结果表明,激活剂浓度在x=0.04时,Sr2-2xCaMoO6:2xEu的荧光性能最佳;采用Li+、Na+、K+做电荷补偿剂均可以提高荧光性能,但Li+、Na+做电荷补偿更有利于提高荧光粉的纯度;采用W与Mo互补掺杂可以明显提高荧光性能,并且可以使电偶极跃迁5D0-7F2增强,当W/Mo比例为1:1时,整体的荧光性能最佳,此外,当W引入Sr2CaMoO6:Eu体系荧光粉中,可以使荧光粉的表面形貌更加规则。(3)实验研究了Sr3WO6:Eu体系荧光粉的荧光性能,该体系荧光粉在近紫外区域有极强的激发,发射效率以及色纯度也非常高,是一种优质的近紫外光芯片用的红粉。实验发现,Sr3-xEuxWO6当掺杂浓度为x=0.3时,整体效果最佳;Sm3+离子不能起到很好的敏化作用;K+离子是一种优质电荷补偿剂,采用K+做电荷补偿可以明显提高荧光性能,制备的样品具有极高的色纯度,色坐标为(0.655,0.339)。
[Abstract]:White light emitting diode (LED) is recognized as the fourth generation lighting source because of its many advantages, such as energy saving and environmental protection, long life, fast response speed, small volume and so on. At present, the realization scheme of white light LED is mainly fluorescence conversion type. However, at present, the red powder efficiency is low and unstable, which limits the development of high color index and high efficiency white light LED. Therefore, it is very important to study the high efficiency red powder conversion suitable for near UV chips. In this thesis, three kinds of red phosphors of Sr2MgWO6:Eu,Sr2CaMO6:Eu,Sr3WO6:Eu system were prepared by a simple sol-gel method. (1) the fluorescence properties of red phosphors of Sr2MgWO6:Eu system were studied experimentally. the relationship between the concentration of activators and luminous properties, the effect of the introduction of Sm3 ions on the luminous properties and the effect of charge compensation on the luminous properties were studied. The experimental results show that when the concentration of activating agent is x 鈮，
本文编号：2498180
[Abstract]:White light emitting diode (LED) is recognized as the fourth generation lighting source because of its many advantages, such as energy saving and environmental protection, long life, fast response speed, small volume and so on. At present, the realization scheme of white light LED is mainly fluorescence conversion type. However, at present, the red powder efficiency is low and unstable, which limits the development of high color index and high efficiency white light LED. Therefore, it is very important to study the high efficiency red powder conversion suitable for near UV chips. In this thesis, three kinds of red phosphors of Sr2MgWO6:Eu,Sr2CaMO6:Eu,Sr3WO6:Eu system were prepared by a simple sol-gel method. (1) the fluorescence properties of red phosphors of Sr2MgWO6:Eu system were studied experimentally. the relationship between the concentration of activators and luminous properties, the effect of the introduction of Sm3 ions on the luminous properties and the effect of charge compensation on the luminous properties were studied. The experimental results show that when the concentration of activating agent is x 鈮，
本文编号：2498180
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