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采用硝酸盐-柠檬酸溶胶凝胶燃烧合成法制备了Er3+掺杂Y2O3上转换发光粉体,研究了不同柠檬酸用量对Y2O3:Er粉体晶体结构、颗粒形貌、颗粒尺寸和上转换发光性能的影响。研究结果表明,柠檬酸加入量的多少不会影响粉体的晶体结构,XRD图谱的衍射峰位置没有发生改变;只是随着柠檬酸的增加,可能会导致晶粒发育不完全,使得参加衍射的晶胞数变少,衍射峰发生明显的宽化。不同柠檬酸加入量下得到的粉体,颗粒尺寸都在纳米级;随着柠檬酸加入量的增加,颗粒尺寸变小,表面能增加,团聚更明显。柠檬酸加入量对发光性能影响较为明显,当柠檬酸与硝酸盐的摩尔比为2时,4S3/2/2H11/2→4I15/2跃迁所对应的绿光发射强度和4F9/2→4I15/2跃迁所对应的红光发射强度都呈现出了最大值。这是因为体猝灭中心与表面猝灭中心对Er3+离子的上转换发光猝灭作用都处于一个相对较弱的状态,同时由于C3 i格位上的Er3+离子的电偶极跃迁的宇称禁戒解除,使得C3 i格位上的Er3+离子的发射增强,这就使得粉体的上转换发光整体增强,并达到最大值。
The upconversion luminescent powders with Er3 + doping Y2O3 were prepared by nitrate-citric acid sol-gel combustion synthesis. The effects of different citric acid dosage on the crystal structure, particle morphology, particle size and upconversion luminescence of Y2O3: Er powders were studied. Impact. The results show that the amount of citric acid added will not affect the crystal structure of the powder and the diffraction peak position of XRD does not change. However, with the increase of citric acid, the crystal growth may not be complete, As the number of the cells decreases, the diffraction peak is significantly broadened. With different amounts of citric acid added, the size of the particles was in the nanometer range. With the addition of citric acid, the particle size became smaller, the surface energy increased and the agglomeration became more obvious. When the molar ratio of citric acid to nitrate is 2, the green light emission intensity corresponding to 4S3 / 2 / 2H11 / 2 → 4I15 / 2 transition and the ratio of 4F9 / 2 → 4I15 / 2 transition corresponding to the red emission intensity showed the maximum value. This is because both the quenching center and the surface quenching center are in a relatively weak state for the up-conversion luminescence quenching of Er3 + ions. At the same time, due to the algebraic ban on the electric dipole transition of Er3 + ions on the C3i With the release of the ring, the emission of Er3 + ions at the C3 i position is enhanced, which makes the upconversion luminescence of the powder increase and reach the maximum.