Preparation of Germanium Oxide Glasses-Based White and Green Phosphors by a Sol-Gel Method

溶胶-凝胶法制备氧化锗玻璃基白光和绿光荧光粉

基本信息

批准号：
15560590
负责人：
KOJIMA Kazuo
金额：
$ 1.79万
依托单位：
Ritsumeikan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560590/
关键词：
Germanium Oxide Glass Sol-Gel Method White Phosphor Green Phosphor Structural Defects Tb^<3+> Ion Mn^<2+> Ion 残光

项目摘要

The XRD analysis determined the time-temperature-transformation(T-T-T) diagram for sol-gel derived GeO_2 gels heated under various conditions of temperature and time. Sol-gel derived GeO_2 glasses were obtained by heating the gels according to the T-T-T diagram. For comparative purposes, GeO_2 glass was prepared by melt-quenching method. The sol-gel derived glasses showed strong, white luminescence (400-700 nm). White afterglow was also observed under irradiation at 254 and 365 nm. On the other hand, the melt-quenched glass gave a luminescence band at 410 nm, and the afterglow was decayed quickly. The sol-gel derived glass included defects and impurities such as Ge^<2+> center, Ge-OH,H2_O,R-OH (R : alkyl group), CH_3-,-CH_2-,CH_3CH_2-,CO_2,Ge-O-C,GeC,Ge-O-R, and carbon-related radicals, while the melt-quenched glass contained Ge^<2+> and GeE' centers, and Ge-OH. The white luminescence and afterglow observed in the sol-gel derived GeO_2 glass are considered to be caused by the Ge^<2+> c … More enter and Ge-O-C.In Tb^<3+> ions doped GeO_2 glasses, under UV excitation at 254 and 365 nm, fluorescence bands due to the transitions of ^5D_4→^7F_j(j=3,4,5, and 6) in the Tb^<3+> ions appeared at 489,544,586, and 620 nm, respectively. In addition, the Tb^<3+> afterglow was observed and lasted longer with increasing the UV irradiation time. However, when the UV irradiation time was too long, the afterglow disappeared quickly. It is found that the intensity of an absorption band due to the tradition 4f^7→4f^65d^1 of the Tb^<4+> ions increased with an increase in the UV irradiation time. Therefore, it is considered that the afterglow may be affected by the Tb^<4+> ions.Mn ion doped ZnO-GeO_2 glasses and glass ceramics were prepared from solutions of (CH_3COO)_2Zn ・2H_20,Ge(OC_2H_5)_4, and Mn(NO_3)_2 ・6H_2O by a sol-gel method and the subsequent heat treatment up to 1000 ℃. Under UV irradiation of 254 or 365 nm, the glass ceramics showed green luminescence at 535 am, which may be due to the ^4T_1→^6A_1 transition of Mn^<2+> ions incorporated in Zn_2GeO_4 polycrystals. The intensity of this green luminescence strengthened and the crystallinity of Zn_2Ge0_4 became high with increasing the heat-treatment temperature up to 1000O℃. In materials with low crystallinity and large amount of MnO, we observed a broad, featureless ESR signal of g=2.01. On the other hand, in a high-crystallinity and low MnO content sample heat treated at 1000℃, 0.1MnO-40ZnO-60GeO_2, many ESR signals were found in the range of about 20 to 500 mT; typical signals having six hyperfine lines were at g=2.01(A=8.3-8.7 mT) and g=4.27 (A=8.2-8.3 mT). All of these ESR signals are probably due to tetrahedrally coordinated Mn^<2+> ions incorporated in Zn_2GeO_4 polycrystals.Local structure around Er^<3+> and Ge^<3+> ions in sol-gel derived GeO_2 glasses were studied by vibrational and XAFS spectroscopy. Less

XRD分析确定了在各种温度和时间条件下加热的溶胶 - 凝胶衍生的GEO_2凝胶的时间温度转换图（T-T-T）图。通过根据T-T-T图加热凝胶获得溶胶 - 凝胶衍生的GEO_2玻璃。出于比较目的，GEO_2玻璃是通过熔融方法制备的。 Sol-Gel衍生的玻璃显示出强烈的白色发光（400-700 nm）。在254和365 nm的辐射下还观察到了白余辉。另一方面，熔化的玻璃在410 nm处产生了发光带，并且余辉迅速腐烂。 The sol-gel derived glass included defects and impurities such as Ge^<2+> center, Ge-OH,H2_O,R-OH (R : alkyl group), CH_3-,-CH_2-,CH_3CH_2-,CO_2,Ge-O-C,GeC,Ge-O-R, and carbon-related radicals, while the melt-quenched glass contained Ge^<2+> and GeE' centers, and ge-oh。在sol-gel派生的geo_2玻璃中观察到的白色发光和余辉被认为是由ge^<2+> c…更多的输入和ge-o-c.in tb^<3+>离子掺杂的geo_2玻璃，在254和365 nm的紫外兴奋下，由于254和365 nm，由于荧光频带，由于uv的荧光频段，ive = 5d_4→^5d_4→^7dd_4→^7df ive。在Tb^<3+>离子中，分别出现在489,544,586和620 nm中。另外，观察到tb^<3+>余辉，并且随着紫外线照射时间的增加而持续更长的时间。但是，当紫外线照射时间太长时，余辉很快就消失了。发现由于TB^<4+>离子的传统4f^7→4f^65d^1引起的吸收带的强度随着UV辐照时间的增加而增加。因此，考虑到余辉可能会受到tb^<4+>离子的影响。Mn离子掺杂的Zno-Geo_2玻璃和玻璃陶瓷是根据（CH_3COO）_2Zn _2zn・2H_20，GE（OC_2H_5）_4 _4 _4，和Mn（no_3）的方法和A sol-_2 _3）_4（_2H_2H_3）_4，_3）_4（_2 i_2）_4（_2zn）的溶液制备了最多1000℃。在254或365 nm的紫外线照射下，玻璃陶瓷在535 AM处显示的绿色发光，这可能是由于^4T_1→^6A__1在Zn_2Geo_4 polycrystals中纳入Mn^<2+>离子的过渡。这种绿色发光的强度增强了，Zn_2GE0_4的结晶度随着热处温度的增加到1000o℃而变得很高。在具有低结晶度和大量MNO的材料中，我们观察到了G = 2.01的广泛，无特征的ESR信号。另一方面，在以1000℃，0.1MNO-40ZNO-60GEO_2处理的高晶和低MNO含量样品中，发现许多ESR信号在约20至500吨的范围内；具有六个超细线的典型信号在g = 2.01（a = 8.3-8.7 mt）和g = 4.27（a = 8.2-8.3 mt）。所有这些ESR信号可能是由于Zn_2Geo_4中掺入的四面体配位Mn^<2+>离子。元素结构围绕ER^<3+>和ge^<3+>离子在Sol-gel衍生的GEO_2中的GE^<3+离子玻璃中通过振动和XAFS镜头进行了研究。较少的