白光LED用氧基磷灰石硅酸盐荧光粉荧光性质研究

发布时间：2018-05-17 03:40

本文选题：氧基磷灰石 + Eu2+　；参考：《温州大学》2015年硕士论文

【摘要】：白光LED因其具有体积小、能耗低、寿命长、高亮度、无污染等优点,被誉为新一代最具价值的绿色光源。寻找能被紫外、近紫外芯片激发的单一基质多光色或全光色荧光粉是现今研究的主流。本文采用高温固相法合成了具有磷灰石结构的LSO(GSO):Eu(2+,3+)和LSO:Eu(2+,3+),Ce3+,Tb3+系列硅酸盐荧光粉并考察了样品在UV、NUV区域激发的发光特性。LSO(GSO):Eu(2+,3+)荧光体中存在两种价态的铕离子。激发到Eu2+,发射光谱中除了常见的5D0发射峰之外还有Eu3+的高能级激发态5D1,2到基态7FJ跃迁的发射峰。激发到Eu2+,LSO:0.30Eu(2+,3+)中5D1(538 nm)能级的寿命为1.10 ms,长于5D0(614.5 nm)能级0.26 ms。GSO:0.30Eu(2+,3+)中5D1(539 nm)和5D2(468nm)能级的寿命分别为1.81 ms、1.65 ms,小于5D0(615.5 nm)能级1.82ms。通过选择激发荧光光谱研究,Eu3+在荧光体中存在三种发光中心。LSO:Eu(2+,3+),Ce3+,Tb3+体系中,Ce3+和Tb3+共掺杂时,改变Tb3+的浓度,得到Ce3+和Tb3+共同发光,Ce3+将一部分能量通过偶极-偶极相互作用机制传递给Tb3+,控制Ce3+/Tb3+的掺杂浓度比,可调变蓝光到绿光发射强度比例,从而实现发光光色调变。Ce3+和Eu3+共掺时,Ce3+向Eu3+传递能量,紫外灯下,随Eu3+浓度增加,试样发光颜色由粉色到红色变化。Ce3+和Eu(2+,3+)共掺的还原试样中,在紫外灯激发下,随铕浓度增加,试样发光颜色由粉色到烛光色变化。Tb3+和Eu(2+,3+)共掺的还原试样中,激发Tb3+的7F6-5D3,发射光谱主要有Tb3+和Eu3+的特征发射峰组成,构成多光色光谱。随着Tb3+浓度的增加,试样在紫外光激发下发光颜色由烛光色到接近白色变化。三种离子共掺时,得到了发射接近白光的试样组成(0.02Ce,0.20Tb,0.20Eu)、(0.01Ce,0.10Tb,0.10Eu)、(0.01Ce,0.15Tb,0.10Eu)。
[Abstract]:White light LED has the advantages of small size, low energy consumption, long life, high brightness and no pollution. It is known as the new generation of the most valuable green light source. Looking for the single matrix multi light color or all light color phosphor which can be excited by ultraviolet and near ultraviolet chips is the mainstream of the present study. In this paper, a high temperature solid phase method has been used to synthesize the LSO with the structure of apatite. (GSO): Eu (2+, 3+) and LSO:Eu (2+, 3+), Ce3+, Tb3+ series of Silicate Phosphors and investigation of the luminescence characteristic of the samples in UV, NUV region and the existence of two valence europium ions. The lifetime of 5D1 (538 nm) energy levels in Eu2+, LSO:0.30Eu (2+, 3+) is 1.10 MS, and is longer than 5D0 (614.5 nm) level 0.26 ms.GSO:0.30Eu (2+, 3+) is 1.81, 1.65, 1.65, less than 615.5. In the.LSO:Eu (2+, 3+), Ce3+, Tb3+ system, Ce3+ and Tb3+ are Co doped, the concentration of Tb3+ is changed, and Ce3+ and Tb3+ are co luminescent. A part of the energy is transmitted to Tb3+ by the dipole dipole interaction mechanism, and the ratio of doping concentration is controlled, and the ratio of blue light to green emission intensity can be adjusted, thus luminous color can be realized. When the modulation.Ce3+ and Eu3+ are Co doped, Ce3+ transfers energy to Eu3+. Under UV light, with the increase of Eu3+ concentration, the luminescence color from pink to red change.Ce3+ and Eu (2+, 3+) Co doped samples, with the UV light excitation, with the concentration of europium increases, the sample luminescence color from powder to candlelight color change.Tb3+ and Eu (2+,) Co doped sample, The emission spectra of 7F6-5D3 of Tb3+ are mainly composed of the characteristic emission peaks of Tb3+ and Eu3+, which constitute a multi light color spectrum. With the increase of Tb3+ concentration, the luminescence color of the sample is changed from candlelight to white. When the three ions are Co doped, the samples (0.02Ce, 0.20Tb, 0.20Eu), which are near the white light, are obtained (0.01Ce, 0.10T). B, 0.10Eu), (0.01Ce, 0.15Tb, 0.10Eu).
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8

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