高效荧光陶瓷制备及其性能研究
文献类型：学位论文
| 作者 | 唐燕如 |
| 文献子类 | 博士 |
| 导师 | 周圣明 |
| 关键词 | 白光LED，荧光陶瓷，铈掺杂钇铝石榴石，光致发光 White LED, Phosphor Ceramic, Ce:YAG, Photoluminescence |
| 其他题名 | Preparation and Properties of High-efficiency Phosphor Ceramics for White LEDs |
| 英文摘要 | 白光LED光源作为照明光源相较于荧光灯以及白炽灯，其具有光效高、能耗低、使用寿命长、环保无污染等特点，因此得到各国政府的极力推广，且目前已逐渐成为主要的照明光源之一。白光LED目前主要采用蓝光LED芯片与黄色荧光粉组合的方式，这种封装方式需要将荧光粉分散在有机树脂或硅胶中。随着人们的照明需求不断提高，这种有机物封装荧光粉的方式已不能满足高功率高显色性能的白光LED的需求。高功率以及高能量密度激发荧光粉将产生大量热量致使有机物加速老化从而导致白光LED的色温色坐标漂移同时使用寿命大大缩短。 为了解决这一问题，白光LED的荧光转换材料的“去有机化”概念提出，因此高性能的荧光玻璃、荧光晶体以及荧光陶瓷得到广泛研究。本论文选择Ce:YAG荧光陶瓷作为研究对象，研究了YAG基质荧光陶瓷的制备方法，并向YAG基质中引入第二相成分以提高荧光陶瓷的光提取效率；同时探究了向Ce:YAG荧光陶瓷中共掺杂红光发光离子或者可改变YAG晶格从而使Ce3+发光峰位红移的离子，以在其荧光光谱中引入红光成分，从而提高荧光陶瓷的显色性能。主要工作如下所示： （1）采用高温固相反应制备Ce:YAG荧光陶瓷，探究了YAG基质的固相反应形成过程，对制备的荧光陶瓷进行白光LED封装并测试其光谱性能，同时将其与市售荧光粉封装的白光LED进行对比。 （2）将Al2O3和MgAl2O4作为第二相掺入Ce:YAG中形成复合相荧光陶瓷，将其与蓝光LED封装形成白光LED,其发光效率显著提高,由相同测试条件下的60lm/W提升至95.41lm/W。建立了第二相掺入Ce:YAG中形成复合相荧光陶瓷的光线传播的模型，证实了第二相引入Ce:YAG中改变荧光陶瓷中光线的传播方向，从而提高Ce3+对于蓝光的吸收效率，同时也提高了荧光陶瓷中光线的出射效率。 （3）向Ce:YAG荧光陶瓷中共掺杂Gd3+，Pr3+，Cr3+中的一种或者两种，形成多掺杂的荧光陶瓷，测试其与蓝光LED封装形成白光LED的发光性能，其发光光谱出现明显的红移或者红光发射峰。将多掺杂荧光陶瓷封装为白光LED，其显色指数较Ce:YAG荧光陶瓷明显提高,由相同色温条件下的60提升至70。 （4）向Al2O3与Ce:YAG形成的复合相荧光陶瓷中掺入Gd3+，Pr3+，Cr3+中的一种或者两种，制备出高性能荧光陶瓷，其与蓝光LED封装为白光LED，既有较高的发光效率同时显色性能也较好。; Nowadays, white light emitting diodes (WLEDs), a new type of luminescent source, have received considerable attention because of their advantage in energy conservation and broad application potential over conventional illumination devices. The current leading commercial WLED normally combines an InGaN blue-emitting chip with Ce:YAG yellow-emitting powder phosphor, and the powder phosphor is packed on the chip surface by using epoxy resin. However, the deterioration of the organic resin matrix, because of its poor heat-resistance, becomes a serious problem under the increasing temperature and output power of LED chips. This raises several issues in WLED practical application, such as degradation of luminous efficacy and long-term reliability, shifts in emission color, and reduction of lifetime. In order to solve the problem, researchers have investigated novel durable phosphors without resins. All-inorganic phosphors are on track to replace the “phosphor powder”-“organic matrix” combination, such as transparent ceramic phosphor and glass ceramic phosphor as practical alternatives to solve the deterioration of the organic resin matrix. In the present study, Ce:YAG phosphor ceramic were fabricated by a solid-state reaction in a vacuum, and furthermore two-phase phosphor ceramic has been made by vacuum sintering. Meanwhile, the introduction of some ions which could effectively increase red-light emission also has been tried for improving the color rendering index. The main contents include: (1) Ce:YAG phosphor ceramics were fabricated by high temperature solid-state reaction. The formation process of YAG matrix solid-state reaction was investigated. Meanwhile, the luminescence properties of the Ce:YAG phosphor ceramic were measured and discussed. (2) The Al2O3 and MgAl2O4 as the second phase were incorporated into the Ce:YAG to form a composite phase phosphor ceramic, and the extraction efficiency for light of the phosphor ceramic was improved significantly. It was confirmed that the second phase introduced in Ce:YAG could change the propagation of the light in ceramic, and thereby it improved the absorption efficiency of Ce3+ to blue light and reduced the total internal reflection. (3) Gd3+, Pr3+ or Cr3+ was co-doped into Ce:YAG phosphor ceramic. The luminescence properties were investigated, and their emission spectra showed obvious red-shift or red light emission peak. The co-doping phosphor ceramic was packaged as a white LED, and its color rendering performance was significantly improved. (4) A composite phase phosphor ceramic formed by Al2O3 and Ce:YAG was doped with Gd3+, Pr3+ or Cr3+ to prepare a high performance phosphor ceramic. The composite phase ceramic phosphor not only improve the luminous efficacy but also enhanced color rendering performance. |
| 学科主题 | 材料学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/31084]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 唐燕如. 高效荧光陶瓷制备及其性能研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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