纳米微孔玻璃制备的新型透明发光材料的研究
文献类型：学位论文
| 作者 | 乔延波 |
| 学位类别 | 博士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 陈丹平 |
| 关键词 | 稀土掺杂 多孔玻璃 高硅氧玻璃 纳米微晶 发光光谱 |
| 其他题名 | Studies of new type transparent luminescence materials fabricated by sintering nanoporous glass |
| 中文摘要 | 激光和光学器件的发展对稀土掺杂玻璃材料提出了更高的要求。玻璃材料在高能和高频激光的应用需要玻璃材料同时具有良好的化学环境稳定性和光学性能，尤其应用在高能激光领域时要求玻璃材料同时具有较高的稀土掺杂浓度和较高的热损伤阈值。石英玻璃由于具有良好的化学稳定性、热膨胀系数小，耐热冲击、低光学损耗和高机械强度，非常适合作为稀土离子基质材料，在很多领域都有重要应用。但是石英玻璃中稀土离子掺杂浓度不高，容易自发团簇产生浓度猝灭效应，不利于器件的小型化，极大地限制石英玻璃的应用。 本文研究了纳米微孔玻璃制备的新型透明发光材料的制备和性质。具有纳米孔的微孔高硅氧玻璃其微孔分布均匀，比表面极大，表面活性高，稀土离子在玻璃中可以得到充分分散。经过低于石英玻璃熔融温度的固相烧结，消除微孔得到密实透明的高硅氧玻璃。高硅氧玻璃中的二氧化硅含量超过96%，成份组成非常接近于石英玻璃，是一种极有前途的发光离子掺杂基质材料。本研究以纳米微孔玻璃为载体，研制新型稀土和过渡金属离子掺杂透明发光玻璃。通过向纳米微孔玻璃中引入发光离子，再经过高温固相烧结制备新型透明发光高硅氧玻璃材料。由于这种材料的良好化学和光学性能，在小型固态激光器，光放大器，显示，光存储，照明等领域有美好的应用前景。本研究得出结论如下: 1、对纳米多孔玻璃的制备和性质有了更详细的研究，优化了纳米多孔玻璃制备工艺。本实验中母体玻璃确定的组成为(mol%)：53.83SiO2-29.80B2O3-8.30Na2O-4.42CaO-3.63Al2O3.本实验中母体玻璃分相热处理是在580℃下处理40h。酸处理过程使用的是1mol/L的硝酸，在100℃条件下酸处理48h或更长。通过以上关键实验参数，我们制备了孔道均匀连通、强度较高、无裂纹的较大尺寸纳米微孔玻璃。通过对纳米微孔玻璃的TEM、BET和吸收光谱等测试分析，对其性质进行了表征。纳米微孔玻璃的组成为：97.0%SiO2-2.1% B2O3- 0.8% Al2O3- 0.1% (Na2O+CaO)，孔径尺寸在10-20nm之间，占孔比为30-40%。 2、研究了纳米微孔玻璃制备的稀土离子掺杂高硅氧红外发光玻璃的光谱性质。Nd3+，Yb3+，Er3+等稀土离子在高硅氧玻璃中的光谱性质被详细的研究。纳米微孔玻璃制备的高硅氧玻璃中稀土离子的掺杂浓度明显提高，一定程度上抑制了发光离子的浓度猝灭。根据不同浓度Nd3+离子掺杂高硅氧玻璃的吸收光谱，利用Judd-Oflet理论计算得到了谱线强度参量Ωt。三个强度参量中，Ω2对玻璃结构和组分的变化最敏感。Ω2与稀土离子的超敏跃迁有关，反映了玻璃中稀土离子周围共价键的数目和环境的不对称性。掺钕高硅氧玻璃的Ω2参数较大，反映了高硅氧玻璃中钕离子周围较低的中心对称环境。向稀土离子掺杂高硅氧玻璃中共掺入Al3+离子有利于玻璃的红外发光，使玻璃发光强度显著提高。 铝离子的掺入使得钕离子的吸收和发光都有明显增强，表明铝离子的掺入有效抑制了钕离子在高硅氧玻璃中的浓度猝灭。但是实验没有明显的证据来证明铝离子的物理分散作用，一般来讲，玻璃中掺入铝离子后如果是物理分散效应在玻璃中起主要作用，将会抑制稀土离子间的交叉弛豫，从而稀土离子的发光量子效率增加。在掺钕高硅氧玻璃中掺入铝离子之后，尽管钕离子的发光强度增加，但是掺钕高硅氧玻璃的荧光寿命相同程度的变短，发光量子效率没有明显的变化。这一结果与铝离子分散玻璃中稀土离子，形成Al—O—RE键抑制浓度猝灭的结论不符。结果表明，RE-Al共掺玻璃中浓度猝灭的有效抑制主要是铝离子的掺入改变了稀土离子周围的结构，而不是简单的物理分散作用。铝离子通过改变结构在玻璃中为稀土离子提供了多样的位置点，稀土离子周围局部发光位置点发生了改变，这种改变有利于稀土离子浓度猝灭的改善。 3、通过在纳米微孔玻璃中引入稀土或过渡金属离子，得到各种新型高效可见发光透明材料。CO气氛中烧结得到的Eu2+掺杂高硅氧玻璃的发光强度是空气中烧结得到的高硅氧玻璃的接近3倍，而使用H2还原气氛烧结之后得到的发光强度是空气气氛烧结样品发光强度的8-10倍。还原气氛是获得高强度蓝光高硅氧玻璃的必要条件。氢气气氛下烧结的Eu2+掺杂高硅氧玻璃在紫外灯激发下具有与照明用商业蓝色荧光粉BaMgAl10O17:Eu2+相当的发光强度，明显强于CRT用商业蓝色荧光粉ZnS:Ag(Cl)的发光强度。实验还发现，即使不用还原气氛甚至氧气气氛下，纳米微孔玻璃中的Eu3+在高温烧结过程中很容易被还原成Eu2+，产生较强的蓝光而不是Eu3+的特征红光发射。将纳米微孔玻璃浸入到铈、锡、铜等离子的溶液中充分吸收，在还原气氛中高温烧结，得到的发光高硅氧玻璃同样具有较强的发光强度。实验表明，烧结气氛的控制对制备高强度发光高硅氧玻璃至关重要。 4、研究了激光与物质相互作用，以发光离子掺杂高硅氧玻璃为基础，研究了玻璃在飞秒激光作用下的上转换可见发光。由于高硅氧玻璃具有很好的耐热性能，化学稳定性和较高的表面激光损伤阈值，在飞秒激光诱导下，可以经受较高功率的激光作用，非常适合作为飞秒激光诱导上转换发光材料。飞秒激光诱导Eu2+掺杂高硅氧玻璃双光子吸收上转换蓝色发光和飞秒激光诱导Cu+掺杂高硅氧玻璃三光子吸收上转换蓝绿色发光现象被详细的研究。 5、本研究实现了微孔玻璃中不同发光离子的空间选择性掺杂，得到了多色集成发光高硅氧玻璃，探讨了这种多色发光玻璃在三维显示中应用的可能性。除了实现发光功能，还可以通过掺入其它离子实现电、磁的方面的功能。如果可以将这些功能和发光功能一起制作到纳米微孔玻璃中，将很有可能实现多功能集成高硅氧玻璃。 6、.首次在纳米微孔玻璃中合成单分散发光纳米微晶，研究了纳米颗粒在高硅氧玻璃中的结构，能量传递以及发光性能。以纳米微孔玻璃为基础，提出了一种制备纳米发光颗粒的新方法。纳米微孔玻璃中具有纳米级的连通微孔，在微孔中生长纳米颗粒，可以有效地限制颗粒的尺寸。而且发光纳米颗粒能够被多孔玻璃的微孔有效地分散，一定程度上避免了发光离子的团簇，降低发生浓度的可能，提高发光性能。以红光YVO4:Eu纳米微晶为对象，研究了发光纳米微晶在微孔玻璃中的合成方法和光学性能。通过XRD，Raman和TEM分析，确认了纳米YVO4:Eu微晶在微孔玻璃中的生长。发光纳米颗粒在玻璃中具有良好的分散性。通过合成YVO4:Eu纳米微晶，有效地抑制了Eu3+离子高温烧结过程中的还原。这种YVO4:Eu透明纳米微晶玻璃在紫外激发下产生的较强的红色发光，具有和商业红粉Y2O3:Eu相当的发光强度。 |
| 英文摘要 | Rare earth (RE)-doped glasses have attracted considerable interests for many optical device applications because of their excellent properties. The request for RE-doped glasses as high power and high repetition laser materials combine desirable environmental stability and high solubility of dopants. Silica glass is an attractive host matrix for the rare-earth ions because of its fine optical and mechanical properties, such as good chemical stability, high UV transparency, strong thermal resistance, low nonlinear index or refractive, high surface damage threshold of laser and large tensile fracture strength. However, the solubility of RE ions in silica glass is low because of concentration quenching. Concentration quenching limits the application of rare-earth-doped silica laser glass used as host matrix. In this thesis, a new type transparent luminescence material was prepared by nanoporous glass. The nanoporous glass has large specific surface area and high surface activity. The homogeneous pores can disperse the RE ions uniformly and improve the solubility of RE ions evidently. After sintering the nanoporous glass impregnating with luminescence ions at about 1100℃, a compact, nonporous and transparent high silica glass was obtained. Because the sintering temperature is much lower than the melting temperature of SiO2, the RE ions in solid state glasses move difficultly during the sintering process and the clustering becomes more difficult in high silica glasses. The content of SiO2 in HSG reaches as high as 96%, close to pure silica glass. We believe this new type transparent luminescence glass has beautiful application future because of its good chemical stability and optical properties. Main achieved results are listed as following: 1. The preparation and properties of nanoporous glass were studied in detail. The composition of the mother glass in the experiment is 53.83SiO2-29.80B2O3-8.30Na2O-4.42CaO-3.63Al2O3. The DTA of the mother glass has two Tg temperature: 542.0℃ and 602.0℃. The heat treatment of the mother was carried out at 580℃ for 40h. The acid treatment was used 1 mol/L HNO3 at 100℃ for 48h or longer. Homogeneous, high mechanical intensity and free of crack nanoporous glass was obtained in this work. The properties of the nanoporous glass was analyzed by TEM, BET and spectral analysis. The analytical composition of the porous glass obtained by phase separating and acid treating was 97.0%SiO2-2.1% B2O3-0.8% Al2O3-0.1% (Na2O+CaO). The porous glass is a transparent material whose pore sizes are about 10-20nm and the pores nominally occupy about 30-40% of the volume of the glass. 2. Nd3+, Yb3+ and Er3+-doped and RE-Al codoped high silica glasses were prepared. Nanoporous structure helps to disperse the RE ions uniformly and improve the solubility of RE ions evidently. 2 is most sensitive to the local structure and glass composition, which reflects the amount of covalent bonding and the asymmetry of the local environment near the rare earth site. The large 2 value suggests a lower centrosymmetric coordination environment around the RE ions in high silica glass. Absorption and fluorescence intensities have remarkable enhancement when aluminum is added into high silica glasses, but fluorescence lifetimes decrease and radiative quantum efficiencies have no remarkable changes. The modification of structures around RE ions is thought to be the main reason that results in the changes of spectroscopic properties. Aluminum is always located near RE ions and aluminum effect on the RE ions is mainly through a local modification of the RE environments. The local structure around RE ions is reorganized by aluminum codoping and the reorganization causes the diversity of luminescent sites for RE ions. These new sites correspond to high energy sites and have consequences on the spectroscopy of Al-RE-codoped glasses. 3. Various visible luminescence high silica glass were fabricated in this work. After the nanoporous glass impregnating with Eu3+ was sintered at 1100℃, the Eu3+ ions were reduced to Eu2+ ions even though the porous glass had been sintered in air. However, the porous glass was sintered at 1100 °C in a reducing atmosphere, the sample showed strong blue emission when excited by UV light. The result indicates that the nanosized, interconnected pores in porous glass are a favorable environment for reducing Eu ions. The emission intensity of Eu2+-doped high silica glass sintered in CO atmosphere was about three times of the sample sintered in air. The emission intensity of Eu2+-doped high silica glass sintered in H2 atmosphere was 8-10 times of the sample sintered in air. The Eu2+-doped high silica glass sintered in H2 atmosphere has comparable emission intensity with the commercial blue phosphor BaMgAl10O17:Eu2+. Ce, Sn and Cu ions doped high silica glass prepared by sintering in a reducing atmosphere also has strong emission. The sintering in appropriate atmosphere is an important process to fabricate high emission intensity high silica glass. 4. The upconversion emission from rare earth and transition ions doped high silica glass excited by femtosecond laser was studied. High silica glass has similar composition with SiO2 glass. Its strong thermal resistance and high surface damage threshold to lasers make it suitable for femtosecond laser induced upconversion luminescence materials. The blue and blue green upconversion emissions from Eu2+ and Cu+-doped high silica glass by femtosecond laser were considered to be related to two and three photons absorption process respectively. 5. Integrated multicolor luminescence patterns were obtained in high silica glass through spatial selective doping different luminescence ions. The possibility to realize full-color, three-dimensional solid-state display in high silica glass was discussed. 6. Single dispersed luminescence nanocrystals were synthesized in nanoporous glass for the first time. Our experiment provides a new method to obtain nanoparticles. Yttrium orthovanadate (YVO4) was chosen as the candidate in this work. YVO4:Eu is a well-known luminescence material which had been used as red phosphor in cathode ray tubes for many years. Well dispersed YVO4:Eu nanocrystals were proved being grown in nanoporous glass by XRD, Micro-Raman spectra and HRTEM equipped with EDS. The YVO4:Eu3+ nanocrystal grown in porous glass shows very different luminescence properties compared with single Eu-doped sample. By this method, intense red emission from high silica glass due to energy transfers VO43-→Eu3+ was obtained. The results shows that the reduction from Eu3+ to Eu2+ in porous glass impregnating with Eu3+ ions was avoided effectively. The transparent high silica glass containing YVO4 nanocrytals has comparable emission intensity with commercial red phosphor Y2O3:Eu. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15256]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 乔延波. 纳米微孔玻璃制备的新型透明发光材料的研究[D]. 中国科学院上海光学精密机械研究所. 2009. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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