几种光色可调荧光粉的制备及性能研究

发布时间：2018-09-19 06:09

【摘要】：白光发光二极管(WLEDs)因为具有安全、节能、环保、高亮以及寿命长等诸多优点而被誉为新一代固体光源。荧光转换型WLEDs(pc-WLEDs)作为制备WLEDs的主流方法,已在显示、背光源、装饰、照明等领域得到了广泛地应用。由于不断发展的照明市场对pc-WLEDs性能(如发光颜色、色饱和度、色温等)的要求越来越趋于精细化,而pc-WLEDs的发光性能又主要取决于荧光粉的发光颜色,因此制备发光颜色可调的荧光粉具有重要意义。基于此,本论文合成了几种光色可调的荧光粉,对其发光性能做出了详细研究,具体研究内容如下:1.采用传统高温固相法合成了一系列Sr_3Lu(PO_4)_3:Dy~(3+),Eu~(3+)荧光粉。在近紫外光激发下,Sr_3Lu(PO_4)_3:Dy~(3+)荧光粉呈冷白光发射,Sr_3Lu(PO_4)_3:Eu~(3+)荧光粉发橙红光。在Sr_3Lu(PO_4)_3:Dy~(3+),Eu~(3+)荧光粉中,Eu~(3+)离子补偿了Dy~(3+)冷白光发射所缺少的红色组分,荧光粉的发光颜色可通过改变Dy~(3+)、Eu~(3+)的相对掺杂浓度从冷白光,到暖白光再到红光进行调控。进一步研究表明在Sr_3Lu(PO_4)_3:Dy~(3+),Eu~(3+)荧光粉中Dy~(3+)通过偶偶极交互作用向Eu~(3+)传递能量。制备的Sr_3Lu(PO_4)_3:Dy~(3+),Eu~(3+)单基质白光荧光粉在pc-WLEDs领域具有潜在应用价值。2.通过高温固相法合成了一系列具有闪铋矿结构的Sr_3(Lu,Tb)(PO_4)_3:Ce~(3+)/Eu~(3+)荧光粉。在233 nm紫外光激发下,Sr_3(Lu,Tb)(PO_4)_3荧光粉的发光颜色可随基质中Tb~(3+)/Lu~(3+)比的增加从蓝色到绿色进行调控。Sr_3Lu(PO_4)_3:0.07Ce~(3+)荧光粉280 nm紫外光激发下发蓝紫光,Sr_3Lu(PO_4)_3:0.30Eu~(3+)荧光粉在395 nm近紫外光激发下发红光。在377 nm近紫外光激发下,Sr_3Tb(PO_4)_3:Eu~(3+)荧光粉中Tb~(3+)能够向Eu~(3+)离子传递能量,荧光粉的发光颜色可通过改变Eu~(3+)的掺杂浓度从绿光到红光进行调控。在Sr_3Tb(PO_4)_3:Ce~(3+)和Sr_3Lu_(0.93-y)Tb_y(PO_4)_3:0.07Ce~(3+)荧光粉中存在Ce~(3+)向Tb~(3+)离子传递能量的过程,在280 nm紫外光激发下,Sr_3Tb(PO_4)_3:Ce~(3+)表现出高亮度绿色发射,Sr_3Lu_(0.93-y)Tb_y(PO_4)_3:0.07Ce~(3+)荧光粉的发光颜色可随Tb~(3+)掺杂浓度的增加从蓝紫光到绿光进行调控。3.通过Pechini-type溶胶-凝胶法成功制备出一系列Sr_(1-x)Eu_xAl_2O_4荧光粉。在262 nm紫外光激发下,Sr_(1-x)Eu_xAl_2O_4荧光粉表现出红色发射。通过两种方式将硼酸加入到基质材料中得到Sr_(0.92)Eu_(0.08)Al_(2-y)B_yO_4和Sr_(0.92)Eu_(0.08)Al_2O_4/yH_3BO_3荧光粉。研究发现硼酸的加入有效地降低Sr_(1-x)Eu_xAl_2O_4荧光粉的成相温度(从1200℃降到了1000 ℃)和提高Eu~(3+)的发射强度。在还原气氛中对Sr_(1-x)Eu_xAl_2O_4和Sr_(1-x)Eu_xAl_2O_4荧光粉进行二次煅烧,实现了二、三价铕共存,Eu~(2+)离子的绿色宽带发射在510 nm左右。通过控制铕离子或硼酸的掺杂浓度,荧光粉的发光颜色可从绿光,到暖白光,再到红光进行调控。研究发现,在空气中经1100 ℃以上烧结的Sr_(0.92)Eu_(0.08)Al_2O_4/yH3BO3(y=0.2~0.5)荧光粉中可以观察到Eu~(3+)→Eu~(2+)自还原现象,此时荧光粉为SrAl_2O_4和Sr4Al2O7混合相,Eu~(2+)的蓝绿色发射宽峰位于491 nm左右,通过改变烧结温度、硼酸加入量或激发光波长均可实现对Eu~(2+)/Eu~(3+)发射强度比的调控,荧光粉实现了青光、白光、红光、黄光等多种光色的发射。
[Abstract]:White light emitting diodes (WLEDs) are known as a new generation of solid-state light sources because of their safety, energy saving, environmental protection, high brightness and long life. Fluorescence-converted WLEDs (pc-WLEDs) have been widely used in display, backlight, decoration, lighting and other fields as the mainstream method of preparing WLEDs. The performance of pc-WLEDs (such as luminous color, color saturation, color temperature, etc.) is becoming more and more refined. The luminous performance of pc-WLEDs mainly depends on the luminous color of phosphors. Therefore, it is important to prepare phosphors with adjustable luminous color. A series of Sr_3Lu(PO_4)_3:Dy~ (3+) and Eu~ (3+) phosphors were synthesized by the traditional high temperature solid-state method. Under the excitation of near ultraviolet light, Sr_3Lu(PO_4)_3:Dy~ (3+) phosphors emitted cold white light and Sr_3Lu(PO_4)_3:Eu~ (3+) phosphors emitted orange red light. Eu~ (3+) ion compensates for the red component lacking in the cold white light emission of Dy~ (3+). The luminescent color of phosphors can be controlled by changing the relative doping concentration of Dy~ (3+), Eu~ (3+) from cold white light to warm white light and then to red light. Further studies show that Dy~ (3+) in Sr_3Lu (PO_4)_3:Dy~ (3+), Eu~ (3+) phosphors can be dipolarly interacted with Eu~ (3+). A series of Sr_3 (Lu, Tb) (PO_4) _3: Ce ~ (3 +) / Eu ~ (3 +) phosphors with bismuth-blending structure were synthesized by high-temperature solid-state method. Under the excitation of 233 nm ultraviolet light, the luminescence of Sr_3 (Lu, Tb) (PO_4) _3 phosphors was studied. The color of Sr_3Lu(PO_4)_3:0.07Ce~(3+) phosphor is blue violet under 280 nm UV excitation, and Sr_3Lu(PO_4)_3:0.30Eu~ (3+) phosphor is red under 395 nm near UV excitation. Under 377 nm near UV excitation, Sr_3Tb(PO_4)_3:Eu~ (3+) phosphor is blue violet. The luminescent color of phosphors can be controlled by changing the doping concentration of Eu~ (3+) from green to red light. In Sr_3Tb (PO_4) _3: Ce ~ (3+) and Sr_3Lu_ (0.93-y) Tb_y (PO_4) _3: 0.07 Ce ~ (3+) phosphors, Ce ~ (3+) can transfer energy to Tb ~ (3 +) ions by changing the doping concentration of Eu ~ (3+). Ce~ (3+) exhibits high brightness green emission, and the luminescence color of Sr_3Lu_ (0.93-y) Tb_y (PO_4) _3:0.07Ce~ (3+) phosphor can be controlled by the blue violet light to green light with the increase of Tb~ (3+) doping concentration. A series of phosphor powders were successfully prepared by the method of Tb~ sol gel method. Under the excitation of 262 UV light, Al_2O_4 phosphors show red emission. Sr_ (0.92) Eu_ (0.08) Al_ (2-y) B_yO_4 and Sr_ (0.92) Eu_ (0.08) Al_2O_4/yH_3BO_3 phosphors were prepared by adding boric acid into the matrix material in two ways. The phase-forming temperature of Sr_ (1-x) Eu_xAl_2O_4 phosphors was decreased from 1200 (1 C) to 1000 (0 (0 C) and the phase-forming temperature of Sr_ (0.92) Eu_ (0) Eu_ (0) E The emission intensity of Eu ~ (2+) is about 510 nm. By controlling the doping concentration of Eu ~ (1 - x) Eu _xAl_2O_4 and Sr (1 - x) Eu _xAl_2O_4 phosphors, the luminescence color of phosphors can be changed from green light to warm white light and then to red light. It is found that Eu~ (3+) Eu~ (2+) self-reduction can be observed in Sr_ (0.92) Eu_ (0.08) Al_2O_4/yH_3BO3 (y=0.2~0.5) phosphors sintered above 1100 C in air. The blue-green emission peak of Eu~ (2+) is about 491 nm. By changing sintering temperature, boric acid addition can be observed. The emission intensity ratio of Eu~ (2+) / Eu~ (3+) can be controlled by the input or excitation wavelength, and the luminescent powder can emit many colors, such as blue, white, red and yellow.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O482.31;TN312.8

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