【作者】 王杰；

【导师】 殷红；

【作者基本信息】 吉林大学 ， 凝聚态物理， 2024， 硕士

【摘要】 稀土发光材料具有发光效率高、颜色纯度好、明亮度高、生态友好等特点,可广泛应用于许多领域,对于未来的照明、显示、激光、信息等领域的发展具有重要作用。本文以六方氮化硼（h-BN）作为载体,通过稀土离子掺杂制备了纳米荧光粉,系统的研究了纳米荧光粉的微观形貌、晶格结构、元素组成和光致发光等性能,并初步探索了在柔性荧光显示领域的应用。主要研究结果如下:1.采用热解法制备了h-BN纳米粉体,发现提高热解温度可以有效地改善h-BN的结晶度,其光学带隙宽度达～5.3 e V,能够实现对深紫外波段的光吸收。光致发光研究表明,h-BN纳米荧光粉在237 nm紫外光照射下在～400 nm处呈现明亮的深蓝发光,发光寿命为14 ns。2.制备了Ce³⁺、Eu³⁺、Tb³⁺稀土离子单掺杂的h-BN纳米荧光粉,结果表明稀土离子的掺入并没有改变h-BN的晶格结构,在1400℃的热解条件下所制备的掺杂材料尺寸均一、形貌稳定,稀土离子以结合态的方式均匀掺入到h-BN当中。对比1400℃热解条件下掺杂前后的h-BN纳米荧光粉发光性能,发现单掺杂的h-BN在355 nm的紫外光激发下可分别实现蓝色、绿色、橙色的不同颜色发光。3.制备了Ce³⁺、Eu³⁺、Tb³⁺三种稀土离子不同配比共掺杂的h-BN纳米荧光粉,结果表明共掺杂时仍然保持h-BN原有的晶格结构,掺杂后的纳米荧光粉中金属氧离子键明显增强,带隙值为3.2 e V,相比未掺杂的h-BN纳米荧光粉明显降低。通过调节稀土离子的掺入比例实现了由234 nm到365 nm波段范围内的紫外光响应,Ce³⁺/Eu³⁺/Tb³⁺=1/0.2/0.2的配比掺杂会得到趋近于明亮白光,发光寿命达0.74 ms,探究了其颜色转变的能量传递机制。此外,制备的h-BN纳米荧光柔性复合材料具有荧光显示的功能。综上所述,稀土离子掺杂h-BN,对调节h-BN的发光效果有着显著的作用,实现可调发光以及对不同波段的紫外光探测,在光功能材料领域有着广阔的应用前景。更多还原

【Abstract】 Rare earth luminescent materials possess several advantageous properties,such as high luminous efficiency,good color purity,high brightness,and ecological friendliness.Due to these characteristics,rare earth luminescent materials demonstrate a wide range of applications in various fields,including lighting,display,laser,and information technology.This paper focuses on the synthesis of nano phosphors by doping rare earth ions into hexagonal boron nitride（h-BN）.The micro-morphology,lattice structure,elemental composition,and photoluminescence properties of these nano phosphors have been systematically investigated.Additionally,their application in flexible fluorescence displays is explored.The main content of the research is as follows:1.The h-BN nano phosphors have been successfully prepared through the pyrolysis method.Increasing the pyrolysis temperature enhances the crystallinity of h-BN,which exhibits an optical band gap of approximately 5.3 e V,allowing for the absorption of deep ultraviolet light.Photoluminescence analysis reveals that under 237nm ultraviolet light excitation,h-BN nano phosphors emit bright deep blue luminescence at around 400 nm,with a luminescence lifetime of 14 ns.2.Mono-doped h-BN nano phosphors with Ce³⁺,Eu³⁺and Tb³⁺rare earth ions have been synthesized.The introduction of rare earth ions does not alter the lattice structure of h-BN.The doping process,conducted at a temperature of 1400℃,yields uniformly sized h-BN nano phosphors with stable morphology.The rare earth ions are incorporated evenly into h-BN in a bound state.Comparisons of the luminescence properties between undoped and mono-doped h-BN nano phosphors reveal that the latter exhibits different colored emissions（blue,green,and orange）under 355 nm UV excitation.3.The h-BN nano phosphors have been co-doped by employing different ratios of Ce³⁺,Eu³⁺,and Tb³⁺rare earth ions.The co-doping process preserves the original lattice structure of h-BN.The co-doped nano phosphors demonstrate a significantly enhanced metal-oxygen ionic bond,resulting in a reduced band gap of 3.2 e V relative to undoped h-BN nano phosphors.By adjusting the inclusion ratio of rare earth ions,UV responses in the wavelength range of 234 nm to 365 nm are achieved.Specifically,the doping ratio of Ce³⁺/Eu³⁺/Tb³⁺=1/0.2/0.2 produces bright white emission with a luminescence lifetime of 0.74 ms.Moreover,the energy transfer mechanism involved in color transformation is explored.Furthermore,the prepared h-BN nano-fluorescent flexible composite exhibits fluorescence display functionality.In conclusion,the doping of rare earth ions in h-BN significantly influences its luminescence properties.This research allows for the achievement of tunable luminescence and the detection of UV light within various wavelength bands.The findings hold significant potential for future applications in the field of optical-functional materials.更多还原