磷酸锆基蓝绿色长余辉发光材料制备及其发光机理

发布时间：2018-05-04 10:51

本文选题：长余辉发光材料 + 掺杂　；参考：《闽南师范大学》2017年硕士论文

【摘要】：长余辉发光材料是一种蓄光节能的绿色环保材料,在标识物、日用工艺品等广泛应用。发光性能优异、化学性能稳定、绿色环保、制造成本低成为衡量长于辉发光材料的重要指标。磷酸盐长余辉发光材料具有绿色环保、化学性能稳定、且易制作等优点。本研究首次报道新型蓝绿色长余辉发光材料ZrP_2O_7:Mn~(2+)的制备。采用高温固相合成法制备以ZrP_2O_7为主体材料,以Zr4+作为发光中心制备蓝绿色长余辉发光材料。通过掺杂低价态的金属离子以及稀土敏化离子以提高材料的发光性能。对材料进行XRD测试并对其物相进行分析,所制备的各种掺杂材料ZrP_2O_7:Mn~(2+),M均归属于标号为PDF:49-1079的标准图谱,掺杂未造成物相的改变但引起晶胞的微小收缩并对材料的结构性能有所改善;对材料进行激发发射光谱测试,并对激发峰及发射峰所对应的微观能级跃迁进行归属,其中位于412 nm、400 nm、382 nm、369 nm及332 nm及附近的激发峰分别归属于Mn~(2+)的6A1→4T1(4G)、6A1→4T2(4G)、6A1→4E、4A1(4G)、6A1→4T2(4D)及6A1→4E(4D)能级跃迁,493 nm附近的发射峰来自于Zr4+,属于蓝光范畴,在545 nm处有一个很弱的发射峰,属于绿光范围,归属于Mn~(2+)离子4T1g→6A1g的能级跃迁,与所观察的蓝绿光一致;对材料的余辉衰减性能进行测试,材料的目测余辉时间可以达到3小时以上;对材料进行热释光谱的测试,并计算其能级陷阱,陷阱深度介于0.2-0.5 eV,深度较合适。通过对材料进行低价离子(Na+、K+、Sr~(2+))掺杂,替代Zr4+以制造材料的内部氧空位缺陷,增加氧缺陷浓度。氧缺陷浓度的增加有利于材料发光性能的改善;此外,掺杂离子的引入也有利于制造深度更加合适的能级陷阱,从而改善材料的发光性能;引入稀土离子(Dy3+、Pr3+、Sm3+)作为敏化离子,利用敏化离子的发射峰能级与发光中心离子能级的交错以达到把敏化离子吸收的光能转移给发光中心从而改善材料的发光性能。材料被光照射后其电子将由基态跃迁到激发态并在材料内部中产生电子空穴对。处于激发态的电子会弛豫到比较低的能级状态,其中大部分直接返回到基态发光,而少部分会被陷阱所捕获并在热扰动下被释放出来跃迁回基态发出光而起到余辉作用。此外因光激发而产生的电子空穴对会在晶格中迁移并在迁移过程中发生相遇而覆灭发光,电子空穴对的寿命影响材料的余辉性能。
[Abstract]:Long afterglow luminescent material is a kind of green environmental protection material, which is widely used in marking, daily handicraft and so on. Luminescence performance, chemical stability, green environmental protection, low manufacturing cost have become an important index to measure the length of luminescent materials. Phosphates long afterglow luminescent materials have the advantages of green environment, stable chemical properties and easy to manufacture. The preparation of a novel blue-green long afterglow phosphor (ZrP_2O_7:Mn~(2) is reported for the first time. The blue-green long afterglow phosphors were prepared by high temperature solid state synthesis with ZrP_2O_7 as the main material and Zr4 as the luminous center. The luminescence properties of the materials were improved by doping metal ions and rare earth sensitized ions. The materials were tested by XRD and their phases were analyzed. All kinds of doped materials, ZrP_2O_7:Mn~(2 + M, were assigned to the standard spectrum of PDF:49-1079. Doping did not change the phase, but caused the tiny shrinkage of the unit cell and improved the structure and properties of the material. The excitation emission spectrum of the material was measured, and the microscopic energy level transition corresponding to the excitation peak and the emission peak was assigned. The emission peaks near 369nm, 332nm and 332nm of 412Nm ~ (1) ~ (4nm) ~ (3 ~ (2) ~ (3) ~ (2) and ~ (3) ~ (32) nm) belong to Zr4 and belong to the category of blue light, respectively, and the emission peaks of 4A1 ~ (4A ~ (1) ~ (4A ~ (1) ~ (4A ~ (1) ~ (4T _ (2) ~ (4D) and 6A1 _ (4E) ~ (4D) are from Zr4 and belong to the category of blue light, and the emission peaks near the excitation peaks are located at 412nm and 332nm, respectively. There is a very weak emission peak at 545nm, which belongs to the green light range and belongs to the energy level transition of Mn~(2) ion 4T1g 6A1g, which is consistent with the observed blue-green light, and the decay performance of the afterglow of the material is measured. The visual luminescence time of the material can reach more than 3 hours, and the pyrorelease spectrum of the material is measured, and its energy level trap is calculated. The depth of the trap is between 0.2-0.5 EV, and the depth is more suitable. In order to make the internal oxygen vacancy defects and increase the concentration of oxygen defects, the Zr4 was replaced by the doping of Na ~ (2 +) -K ~ (2 +) ~ (2 +) ~ (2 +) in the materials. The increase of oxygen defect concentration is beneficial to the improvement of the luminescence performance of the material, in addition, the introduction of doping ions is also beneficial to the fabrication of energy level traps with more suitable depth, thus improving the luminescent properties of the materials. Rare earth ion (Dy3 + Pr3 + Sm 3) was introduced as sensitized ion. The luminescent properties of the sensitized ion were improved by the interleaving of the emission peak energy level of the sensitized ion and the ion level of the luminous center to transfer the light energy absorbed by the sensitized ion to the luminescent center. When the material is irradiated by light, the electrons will transition from ground state to excited state and the electron hole pair will be generated in the material. The electrons in the excited state will relax to the lower energy level state, most of them will return directly to the ground state to emit light, while a few will be trapped by the trap and released under the thermal disturbance to transfer back to the ground state to emit light, which will play an afterglow effect. In addition, the electron hole pair generated by light excitation will migrate in the lattice and meet during the migration process, and the lifetime of the electron hole pair will affect the afterglow properties of the material.
【学位授予单位】：闽南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O482.31

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