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LED用低熔点发光玻璃的研究

Research on Low Melting Luminescent Glass for White-light-LED

【作者】 陈珍霞

【导师】 程金树;

【作者基本信息】 武汉理工大学 , 材料学, 2010, 硕士

【摘要】 白光LED具有耗电量小、寿命长、环保、响应速度快等优点。随着发光效率的提高和生产成本的降低,白光LED必将成为继白炽灯、荧光灯、高强度放电灯后的新一代照明光源。随着白光LED制备技术的不断发展以及其应用领域的不断扩展,白光LED用的荧光材料的性能和制备越来越受到人们的重视。尤其是可被蓝光激发的黄光荧光粉的性能,直接影响白光LED的质量。本文总结了现阶段白光LED的研究现状,比较各种实现白光方式之间的优缺点,提出了研究发光玻璃的必要性。本文以Li2O-B2O3纯硼酸盐、Na2O-Al2O3-B2O3硼酸盐、Na2O-Al2O3-B2O3-SiO2硼硅酸盐、Li2O-ZnO-B2O3-SiO2和Na2O-ZnO-B2O3-SiO2体系的低熔点玻璃作为基质玻璃,采用两步法制备了LED用掺YAG-Ce黄光荧光粉低熔点发光玻璃。利用X射线衍射仪对样品的物相结构进行分析;通过荧光光谱仪测试了样品的激发光谱和发射光谱;借助扫描电子显微镜对样品的微观结构和形貌进行表征。结果表明:1.处理温度的升高,荧光粉的晶相没有发生改变,晶胞参数呈增大的趋势,荧光粉的发光强度呈下降的趋势;保温温度为<900℃时,色坐标未出现明显的变化。相同温度不同保温时间/相同温度不同气氛,荧光粉的发光强度和色坐标都没有明显变化。2.硼硅酸盐基质玻璃C比纯硼酸盐A和硼酸盐玻璃B更适合作为发光玻璃的基质玻璃。随着荧光粉掺入量的增加,B/C系列发光玻璃的发射峰位和峰形没有发生明显的变化;发光强度先升高后降低;色坐标发生微小变化;荧光粉最佳掺入量为玻璃粉与荧光粉质量比为1:0.5。3.以锂锌硼硅酸盐D低熔点玻璃为基质玻璃,浇铸成型为D玻璃,水淬成型为Dw玻璃。采用两步法制备得到的D/Dw系列发光玻璃,随着荧光粉掺入量的增加,试样发射光谱中发射峰的峰形和峰位没有发生变化,发光玻璃的发光强度呈先增加后减小的趋势;色坐标发生微小变化。D和Dw系列发光玻璃的荧光粉最佳掺入量为玻璃粉与荧光粉质量比为1:0.5-1:0.7。4.以封接玻璃钠锌硼硅酸盐E低熔点玻璃为基质玻璃,采用两步法制备得到的发光玻璃,不同烧结气氛:空气气氛EA,氮气气氛EN。EA和EN系列发光玻璃发光强度,后者大部分强于前者:随着掺入荧光粉量的增加,发光强度变化趋势,前者为增强趋势,后者为先增强后降低的趋势;色坐标变化不大;荧光粉最佳掺入量为玻璃粉与荧光粉质量比为1:0.3-1:0.5。本研究得到湖北省教育厅科学技术研究计划重大项目(20091g0041)的资助。

【Abstract】 White-light emitting diodes (LED) possess such excellent performance as low power consumption, long lifetime, environmental protection and fast response time, and so on. Along with increasing of LED luminous efficiency and declining of manufacture costs, it is forecasted that white-light LED will become the new generation lighting and replace incandescent lamp, fluorescent lamp and high intensity discharge lamp and other types of lamp. The synthesis and characterization of phosphors used for white LED were paid more attention with the extension of application and the development of preparation technology in white LED. Especially, the properties of phosphor excited by blue light affect directly the quality of white LED. This article summarizes the research status in quo of white LED’s, will compare the advantages and disadvantages between the realization of white ways, the study proposed the need for fluorescent glass.A series of phosphor doped fluorescent glass based on Li2O-B2O3 low melting pure borate、Na2O-Al2O3-B2O3 borate, and Na2O-Al2O3-B2O3-SiO2 borosilicate glass C, Li2O-ZnO-B2O3-SiO2 borosilicate glass and Na2O-ZnO-B2O3-SiO2 borosilicate glass was prepared by two-step method. The phase’s structures of samples were analyzed by X-ray Powder diffraction meter (XRD). Excitation spectra and emission spectra of samples were measured by fluorescence spectrometer. Microstructure and grain shape of samples were identified by scanning electron microscopy (SEM) and super depth of field microscope. Particle size distributions of phosphors were measured by grain size instrument.1. The phase of YAG phosphors did not change as the treated temperature arises. But its cell parameters increase and the emission bands decrease. The color coordinates did not change significantly when temperature below 900℃. The emission bands and color coordinates were not affected by treated time and atmosphere.2. Borosilicate glass C is more appropriate than pure borate A and borate low melting glass B as the base of fluorescent glass. The emission peak and its shape are not affected by the changes of phosphors’quality adopted in. the intensity of emission bands increased first and than decreased as the phosphor adopted increased. Color coordinates alter slightly when adopted quality increase. The best ratio of glass and YAG phosphors is 1:0.5.3. The based glass zinc borosilicate glass was molded by casting and water quenching, marked as D and Dw respectively. The serials of D and Dw fluorescent glass was prepared by two-step method. The emission peak and its shape are not affected by the changes of phosphors’quality adopted in. The intensity of emission bands increased first and than decreased as the phosphor adopted increased. Color coordinates alter slightly when adopted quality increase. The best ratio of glass and YAG phosphors is 1:0.5~1:0.7.4. The serials of EA/EN fluorescent glass based on sealing glass E, were sintered in air and N2 atmosphere respectively. The serial of EN is better than EA. The intensity of emission bands increased as the phosphor adopted increased in EA. The intensity of emission bands increased first and than decreased as the phosphor adopted increased in EN. Color coordinates alter slightly when adopted quality increase first and than decreased as the phosphor adopted increased. The best ratio of glass and YAG phosphors is 1:0.3~1:0.5.The Project was supported by Educational Commission of Hubei Province of China (20091g0041).

【关键词】 LED低熔点发光激发光谱发射光谱
【Key words】 LEDlow meltingluminescentemissions spectraexcitation spectra
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