【作者】 王鑫；

【导师】 王鹏飞；

【作者基本信息】 哈尔滨工程大学 ， 光学工程， 2020， 博士

【摘要】 稀土离子掺杂的发光材料由于其在显示、激光、防伪、生物等领域的重要应用吸引了科研工作者的广泛研究。在稀土离子和过渡金属离子参与的光致发光过程中,其发光强度通常与基质材料的声子能量成反比。在常见的玻璃材料中,氟化物由于具有远低于氧化物的声子能量,使其成为了上转换发光的首选基质。但是低声子能量的玻璃材料通常伴随着较差的机械性能和化学稳定性,这严重限制了上转换发光材料的应用。如何协调解决玻璃的发光性能和机械化学稳定性这一对矛盾关系,实现对玻璃光学性能和机械、化学稳定性的调控,成为了科研工作者急需解决的难题。在本论文中,我们基于一种具有特殊分相结构的玻璃体系,成功制备了具有优异发光和激光特性的稀土离子掺杂氟硅酸盐玻璃和微晶玻璃。通过控制稀土离子在玻璃基质中的分布方式,实现了有效的上、下转换发光,同时保证了材料整体具有优异的机械性能和化学稳定性。成功解决了“材料的发光性能和稳定性不能同时提高”这一矛盾问题。本论文的具体工作如下:1.制备了Yb3+-Er3+离子共掺杂的新型氟硅酸盐玻璃。其内部具有分相结构,分为富氟区和富硅区。这种特殊的内部结构,导致稀土离子在玻璃基质内部并不是均匀分布,而是在富氟区产生富集。这种局部富集的分布方式,大大缩短了敏化离子Yb3+和发光离子Er3+的距离,进而提高了 Yb3+离子向Er3+离子之间的能量传递效率;同时,富氟区为Yb3+离子和Er3+离子提供了一个低声子能量的环境,减小了电子的非辐射跃迁概率,提高了发光效率。而玻璃中的富硅区,使得玻璃样品整体具有接近石英玻璃的化学和机械稳定性。2.在Yb3+离子单掺的氟氧化物微晶玻璃中,利用玻璃内部的分相结构,使Yb3+离子形成Yb3+-Yb3+离子对,在980nm激光泵浦下,产生高效的蓝光上转换发光。并且在微晶化处理之后,得到透明的Yb3+离子掺杂氟氧化物微晶玻璃样品。在经过微晶化处理后,Yb3+离子的蓝光上转换强度增加了 5倍。3.制备了 Yb3+-Mn2+离子共掺杂的氟硅酸盐玻璃以及透明微晶玻璃样品,在室温环境下,首次实现了Mn2+离子在玻璃材料中的宽带上转换发光;并通过调节掺杂离子浓度,实现了可调谐多彩上转换发光。将玻璃样品进行微晶化处理后,Mn2+离子的上转换发光强度增强了 45倍。这项研究打破了 Mn2+离子上转换发光对晶体材料的依赖,对宽带可调谐发光以及显示照明等领域有着重要的应用。4.利用太阳光泵浦,在Yb3+-Cr3+离子共掺的氟氧化物微晶玻璃中实现近红外荧光发射。通过Yb3+离子与Cr3+离子共掺杂,Cr3+离子吸收太阳光光子,并将能量传递给Yb3+离子,实现近红外发射。在太阳光模拟器的泵浦下,我们观测到了来自Yb3+离子的强烈的近红外荧光发射。对样品进行微晶化处理后,在玻璃中析出了纳米级别的KZnF3晶体。微晶为稀土离子提供了一个更低的声子能量环境,Cr3+离子和Yb3+离子同时进入到晶体环境中,样品的上转换发光增强了 15倍。5.以Nd3+/Tm3+离子掺杂的氟硅酸盐玻璃为基质材料,制备了具有高Q值,低阈值,高激光损伤阈值的Tm3+/Nd3+离子掺杂的氟硅酸盐玻璃微球激光器。该微球激光器的品质因子(Quality,Q)高达1.4×106。我们通过对比氟硅酸盐玻璃和其他3种不同体系玻璃的玻璃转变温度,间接证明了该微球激光器具有高于其他多组分玻璃微球激光器的激光损伤阈值。更多还原

【Abstract】 Rare earth ions-doped luminescent materials have attracted extensive research by scientific researchers due to their important applications in the fields of display,laser,anticounterfeiting,and biology.In the progress of photoluminescence in rare earth doped glass materials,the effective photoluminescence is inversely proportional to the phonon energy of host materials.In common glass materials,fluoride has much lower phonon energy than oxides,making it the preferred substrate for upconversion luminescence.However,low phonon energy glass materials are often accompanied by poor mechanical properties and chemical stability,which severely limit the application of upconversion luminescent materials.Solving the contradictory problems of the luminescent performance and the mechanochemical stability of glass has become a difficult problem for scientific researchers.In order to solve this hot issue,this paper does the following:1.Enhanced upconversion lasing and luminescence is obtained in a transparent compound fluorosilicate glass codoped with Yb3+ and Er3+ ions.The sample is prepared by a conventional melting-quenching technique followed by a heat treatment,and a very high upconversion efficiency is achieved.The physical processes involved start from a phase-separated,as-melt fluorosilicate glass consisting of fluorine-rich domains,which provide the low photon energy environment for Er3+ ions.This presents a significant improvement in the development of visible light sources for microphotonics applications.2.Yb3+-doped oxyfluoride glasses and glass ceramics containing KZnF3 nanocrystals were obtained by melt-quenching.Under excitation of a 980 nm laser,a strong blue emission from Yb3+-Yb3+ cooperative upconversion was observed in the glass and glass ceramics sample.Fluroide phase provides a low-phonon-energy environment for Yb3+-Yb3+ion pairs,which facilitates an intense fluorescent blue emission in the KZnF3 crystal lattice.Both theoretical and experimental results demonstrate that Yb3+-doped oxyfluoride glasses and glass ceramics containing KZnF3 nanocrystals are promising materials for blue upconversion emission.3.In contrast to well-known upconversion(UC)emission from Yb3+-Mn2+co-doped crystal,a room-temperature intense broadband UC phenomenon was first observed both in Yb3+-Mn2+co-doped fluorosilicate glasses and transparent glass ceramics under 980 nm pumping.The obtained photoluminescence(PL)ranged from yellow to white to blue.We attributed this effect to the cooperative UC of Yb3+and to the formation of Yb3+-Mn2+pairs.After heat treatment,KZnF3 nanocrystals appeared in the glass matrix,as identified by X-ray diffraction(XRD)and transmission electron microscopy(TEM),and the emission intensity increased 45 times.We believe that Yb3+-Mn2+co-doped glasses or glass ceramics show great potential as a material for multi-color displays.4.Cr3+-Yb3+ codoped bulk glass-ceramics containing KZnF3 nanocrystals are fabricated by thermal treatment.The luminescent properties of the glass and glass ceramic are investigated from the measured photoluminescence spectra and fluorescent lifetime.The measurement results demonstrate that Cr3+ and Yb3+ions have both entered the KZnF3 lattice in the glass ceramic,and the energy absorbed by Cr3+ions is efficiently transferred to Yb3+ions when excited at 450 nm.The obtained results indicate that the Cr3+-Yb3+ codoped KZnF3 glass ceramic provides a promising material for spectral conversion from visible sunlight to nearinfrared emission and a novel gain material for solar pumped fiber laser.5.High Q factor microsphere resonators with excellent stability and high damage threshold are fabricated from Tm3+doped fluorosilicate glasses using the traditional melt-quenching and fiber heating techniques.Intense 1.88 μm photoluminescence and single mode laser emission are obtained under the excitation of an 808 nm laser.The Q factor of the microsphere resonator is measured to be as high as 1.4×106.Models for photoluminescence and lasing are proposed using spectroscopic data from the absorption and emission spectra.更多还原