2016年5月11日
Anomalous Orange Light-Emitting (Sr,Ba)2SiO4:Eu(2+) Phosphors for Warm White LEDs.
ACS applied materials & interfaces
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- 巻
- 8
- 号
- 18
- 開始ページ
- 11615
- 終了ページ
- 20
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/acsami.6b02237
Phosphors with sufficient red emission component are necessary for warm white light-emitting diodes. In this work on (Sr,Ba)2(1-x)Eu2xSiO4 phosphors, (Sr,Ba)1.5Eu0.5SiO4 achieved 75% of an internal quantum efficiency under excitation by blue light. Surprisingly, the (Sr,Ba)1.5Eu0.5SiO4 exhibited orange emission, against the well-known traditional green-yellow emission of (Sr,Ba)2SiO4:Eu(2+). Moreover, the concentration quenching of Eu(2+) in (Sr,Ba)2SiO4 was abnormally unobvious. With the help of calculations based on the density functional theory, it was discovered that the distinct local environment of luminescence centers rather than usual explanation such as self-absorption or intensified crystal field splitting, is responsible to the interesting red shifts in excitation and emission spectra. The refinement analysis based on X-ray diffraction revealed that the unequal distribution of Eu(2+) to two crystallographic sites caused low concentration of Eu(2+) at the 9-coordination site, inhibiting the concentration quenching. The (Sr,Ba)1.5Eu0.5SiO4 phosphor has warmer emission than the commercial Y3Al5O12:Ce(3+). This study also promotes research on the effect of site occupancy and the local environment of luminescence centers.
- ID情報
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- DOI : 10.1021/acsami.6b02237
- PubMed ID : 27090069