Enhanced optical and thermal performance of white light-emitting diodes with horizontally layered quantum dots phosphor nanocomposites
Enhanced optical and thermal performance of white light-emitting diodes with horizontally layered quantum dots phosphor nanocomposites
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DOI：
10.1364/prj.6.000090
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发表时间：
2018-02-01
影响因子：
7.6
通讯作者：
Yu, Binhai
中科院分区：
文献类型：
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作者：
Yu, Shudong;Tang, Yong;Yu, Binhai
具有传统荧光粉和量子点的白色发光二极管（WLED）由于其良好的显色能力而受到越来越多的关注。然而，它们的光学和热性能仍然受到限制，特别是对于具有量子点-荧光粉混合纳米复合物的那些。在这项工作中，我们提出了一种新型的水平分层量子点-荧光粉纳米复合材料封装方案，以获得增强的WLED光学和热性能。制作了三种不同的WLED，包括量子点-荧光粉混合型，量子点-外部型和量子点-内部型，并进行了比较。30 wt. %磷光体和0.15wt.结果表明，当量子点纳米复合材料的质量分数为0.5%时，与混合型WLED相比，量子点外型WLED的发光效率提高了21.8%，显色性更好，400 mA时的最高温度降低了27.0%。荧光粉和量子点之间减少的再吸收是当它们被分离时性能增强的原因。然而，这种降低的吸收可以通过不适当的分层配置来权衡，这通过QD内部类型的最差性能来证明。此外，我们证明了量子点外型WLED中激发光和纳米复合材料之间更高的能量转移效率是其增强光学和热性能的关键原因。(c)2018中国激光出版社
Due to their good color rendering ability, white light-emitting diodes (WLEDs) with conventional phosphor and quantum dots (QDs) are gaining increasing attention. However, their optical and thermal performances are still limited especially for the ones with QDs-phosphor mixed nanocomposites. In this work, we propose a novel packaging scheme with horizontally layered QDs-phosphor nanocomposites to obtain an enhanced optical and thermal performance for WLEDs. Three different WLEDs, including QDs-phosphor mixed type, QDs-outside type, and QDs-inside type, were fabricated and compared. With 30 wt. % phosphor and 0.15 wt. % QDs nanocomposite, the QDs-outside type WLED shows a 21.8% increase of luminous efficiency, better color rendering ability, and a 27.0% decrease of the maximum nanocomposite temperature at 400 mA, compared with the mixed-type WLED. The reduced re-absorption between phosphor and QDs is responsible for the performance enhancement when they are separated. However, such reduced absorption can be traded off by the improper layered configuration, which is demonstrated by the worst performance of the QDs-inside type. Further, we demonstrate that the higher energy transfer efficiency between excitation light and nanocomposite in the QDs-outside type WLED is the key reason for its enhanced optical and thermal performance. (c) 2018 Chinese Laser Press