Crystal structure and luminescence properties of the blue‐green‐emitting Ba9(Lu,Y)2Si6O24:Ce3+ phosphor |
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Authors: | Huawei Xu Zhi Zhou Yongfu Liu Qunxing Liu Zhiyuan He Shen Wang Linyi Huang Hongbo Zhu |
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Affiliation: | 1. The Fifth Research Institute of MIIT, Quality Inspection and Testing Center, Guangzhou, China;2. College of Science, Hunan Agricultural University, Changsha, China;3. Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, China;4. Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, China |
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Abstract: | Samples of the Ba9(Lu2‐xYx)Si6O24:Ce3+ (x = 0–2) blue‐green phosphors were synthesized by solid‐state reactions. All the samples exhibited a rhombohedral crystal structure. As the Y3+ concentration increased, the diffraction peaks shifted to the small angle region and the lattice parameters increased due to the larger ionic radius of Y3+ (r = 0.900 Å) compared with that of Lu3+ (r = 0.861 Å). Under 400 nm excitation, samples exhibited strong blue‐green emissions around 490 nm. The emission bands had a slight blue shift that resulted from weak crystal‐field splitting with increasing Y3+ concentration. Luminescence intensity and quantum efficiency (QE) decreased with increasing Y3+ concentration. The internal QE decreased from 74 to 50% and the external QE decreased from 50 to 34% as x increased from 0 to 2. The thermal stability of the Lu series was better than that of the Y‐series. The excitation band peak around 400 nm matched well with the emission light from the efficient near‐ultraviolet (NUV) chip. These results indicate promising applications for these NUV‐based white light‐emitting diodes. |
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Keywords: | blue‐green phosphor Ce3+ luminescence near ultraviolet silicate white LEDs |
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