镓酸盐荧光粉的发光性能调控及应用研究

【作者】 张颖；

【导师】 丁召；

【作者基本信息】 贵州大学 ， 集成电路工程， 2025， 硕士

【摘要】 相较于传统的照明技术,白色发光二极管拥有寿命长、节能等优点,其正开始逐步取代传统的白炽灯等照明技术,在制作上需要将荧光粉与发光芯片进行组合封装使用。在显示技术领域,其性能通常由显示器本身的亮度、色彩表现力以及均匀性和稳定性来评估。因此,探索性能优异的荧光粉对推动显示器件性能的提升具有重要意义。本文采用CaYGaO₄作为基质,材料中的Ca和Y原子可以通过掺杂不同离子进行取代,实现不同的发光,从而得到不同颜色的荧光粉。1、通过采用高温固相法合成了CaYGaO₄:Eu³⁺(CYGO:Eu³⁺)荧光粉。采用X射线衍射仪（XRD）和扫描电子显微镜（SEM）对复合材料进行了表征。利用X射线能谱（EDS）和X射线光电子能谱（XPS）对样品的微观组成进行了分析。基于第一性原理方法计算了CYGO和CYGO:0.25Eu³⁺的禁带宽度和态密度。荧光光谱显示样品在紫外光和蓝光区域具有强烈的激发峰。CaYGaO₄:Eu³⁺荧光粉拥有优异的热稳定性能,当样品加热到473 K时,在393 nm和463 nm激发下的发光强度分别保持在室温的83.99%和85.19%。将CYGO:Eu³⁺荧光粉封装制成WLED,该WLED色坐标为（0.3338,0.3521）,相关色温为5448 K,显色指数（CRI）为Ra=86.2。此外,使用样品混合制成的防伪油墨在紫外灯的照射下具有强烈的辨识度。因此,CYGO:Eu³⁺荧光粉在WLED领域以及防伪油墨领域具有良好的应用前景。2、通过高温固相反应合成了系列单相CaYGaO₄:Dy³⁺(CYGO:Dy³⁺)荧光粉。通过不同方式的表征对其物相进行了表征。在荧光光谱中,其激发峰主要由蓝光区的485nm和黄光区的570nm组成。样品拥有良好的热稳定性。在473 K下347nm激发的发射强度约为室温发射强度的70.9%。将荧光粉与365 nm发光芯片进行了集成封装获得暖白光,其CIE坐标为（0.4413,0.4181）,CCT为3066 K。CYGO:Dy³⁺荧光粉可应用于WLED领域。3、首次通过高温固相法在1350℃下煅烧5 h得到CaYGaO₄:Er³⁺(CYGO:Er³⁺)荧光粉,通过X射线衍射仪扫射证明Er³⁺离子成功掺杂到了CaYGaO₄。通过测试样品的吸收光谱,峰的位置符合Er³⁺离子的特征峰,同时Er³⁺离子的掺杂导致了CYGO的能带发生了微小的降低,伴随着掺杂剂量的增加,禁带宽度呈现下降的趋势。实验样品的荧光光谱显示了样品在绿色区域具有强烈的发射峰。通过CIE1931研究了样品的色度坐标、色纯度以及相关色温。CaYGaO₄:Er³⁺荧光粉可以作为合成WLED的单相绿色荧光粉。4、通过高温固相法合成了CaYGaO₄:Eu³⁺,Bi³⁺(CYGO:Eu³⁺,Bi³⁺)荧光粉。荧光光谱中展示了Bi³⁺和Eu³⁺的特征峰,同时样品中根据掺杂离子浓度的差异,样品显现出了不同的颜色,CIE1931的色度坐标图展示了样品从高色温到低色温的变化过程。将样品与商用绿色荧光粉混合封装的WLED器件中,所获得白光相关色温为5418 K,显色指数为76.2,CIE坐标为（0.334,0.3263）,接近标准白光坐标。CYGO:Eu³⁺,Bi³⁺荧光粉提供了一种新型的合成白光的方式,可用于WLED领域。更多还原

【Abstract】 Compared with traditional lighting technology,white light-emitting diodes have the advantages of long life and energy saving,and they are beginning to gradually replace the traditional incandescent lamps and other lighting technologies,which require a combination of phosphors and light-emitting chips to be encapsulated for use in their production.In the field of display technology,its performance is usually evaluated by the brightness,color expression,and uniformity and stability of the display itself.Therefore,exploring phosphors with excellent performance is of great significance to promote the performance of display devices.In this thesis,CaYGaO₄is used as the substrate,and the Ca and Y atoms in the material can be replaced by doping with different ions to achieve different luminescence,thus obtaining phosphors of different colors.1.CaYGaO₄:Eu³⁺(CYGO:Eu³⁺)phosphors were synthesized by employing a high-temperature solid-state method.The composites were characterized by X-ray diffractometry（XRD）and scanning electron microscopy（SEM）.The microcomposition of the samples was analyzed using X-ray energy spectroscopy（EDS）and X-ray photoelectron spectroscopy（XPS）.The forbidden bandwidths and density of states of CYGO and CYGO:0.25Eu³⁺were calculated based on the first principles method.The fluorescence spectra showed that the samples possessed strong excitation peaks in the UV and blue regions.The CaYGaO₄:Eu³⁺phosphors possessed excellent thermal stability properties,and the luminescence intensities of the samples under 393 nm and 463 nm excitations were maintained at 83.99%and 85.19%of the room temperature when the samples were heated up to 473 K.The fluorescence intensity of the samples under 393 nm and 463 nm excitations was also maintained at83.99%and 85.19%of the room temperature,respectively.The CYGO:Eu³⁺phosphor was encapsulated to make a white light-emitting diodes（WLEDs）,which had a color coordinate of（0.3338,0.3521）,a correlation color temperature of 5448 K,and a color rendering index（CRI）of Ra=86.2.In addition,the anti-counterfeiting inks made by using a mixture of the samples were strongly discriminative under the irradiation of UV lamps.Therefore,CYGO:Eu³⁺phosphors have good application prospects in the field of WLEDs as well as in the field of anti-counterfeit inks.2.A series of single-phase CaYGaO₄:Dy³⁺(CYGO:Dy³⁺)phosphors were synthesized by high-temperature solid-state method.Their physical phases were characterized by different ways of characterization.In the fluorescence spectrum,the excitation peaks were mainly composed of 485 nm in the blue light region and 570nm in the yellow light region.The sample possesses good thermal stability.The emission intensity of 347 nm excitation at 473 K is about 70.9%of the room temperature emission intensity.The phosphor was integrated and packaged with a 365nm light-emitting chip to obtain warm white light with CIE coordinates of（0.4413,0.4181）and a CCT of 3066 K.CYGO:Dy³⁺phosphor can be used in WLEDs.3.CaYGaO₄:Er³⁺(CYGO:Er³⁺)phosphor was obtained for the first time by high-temperature solid-phase calcination at 1350℃for 5 h.It was proved that Er³⁺ions were successfully doped into CaYGaO₄by X-ray diffraction scanning,and the position of the peaks was in accordance with the characteristic peaks of Er³⁺ions through the absorption spectra of the samples tested,and at the same time the doping of Er³⁺ions resulted in a slight decrease in the energy bands of CYGO.energy band undergoes a slight decrease,and the forbidden band width shows a decreasing trend along with the increase of the doping dose.The fluorescence spectra of the experimental samples showed strong emission peaks in the green region.The chromaticity coordinates,color purity,and the associated color temperature of the samples were investigated by CIE1931.CaYGaO₄:Er³⁺phosphors can be used as single-phase green phosphors for the synthesis of WLEDs.4.CaYGaO₄:Eu³⁺,Bi³⁺(CYGO:Eu³⁺,Bi³⁺)phosphors were synthesized by a high-temperature solid-state method.The fluorescence spectra exhibited characteristic peaks for Bi³⁺and Eu³⁺,while the samples displayed varying colors based on the concentration of the dopant ions.The chromaticity coordinate plot of CIE 1931illustrated the transition of the samples from high color temperature to low color temperature.In WLED devices,where the samples were mixed and encapsulated with commercial green phosphors,the resulting white light had a correlated color temperature of 5418 K,a color rendering index of 76.2,and CIE coordinates of（0.334,0.3263）,which are close to the standard white light coordinates.The CYGO:Eu³⁺,Bi³⁺ phosphors offer a novel approach to synthesizing white light,making them suitable for applications in the field of WLEDs.更多还原