Quantum dots (QDs) are usually used with phosphor to obtain white light-emitting diodes (WLEDs) due to their excellent lighting characteristics. For lighting effect improvement, the QDs layer and the phosphor layer are supposed to be separated to reduce reabsorption loss and enhance QDs stability. Based on the separated structure, a QDs/boron nitride hybrid reflective (QBHR) structure is proposed to enhance the optical performance of WLEDs in this study. QDs were electrostatically bonded on the boron nitride (BN) pellets and their composite particles were subsequently mixed with silicone for LED encapsulation by a spinning-coated process. It could be easily managed the performance of QBHR structure by controlling the composite particles’ concentration or centrifugal speed. The diffuse reflectance and photoluminescence (PL) intensity of QBHR structure with various thicknesses were analyzed. While applying with remote phosphor layer for WLEDs, the luminous efficacy of devices with QBHR structure increases with phosphor concentration, which are larger than that of QD/polydimethylsiloxane (QP) structures. It may be caused by the light extraction ability of the scattering BN particles and high color conversion efficiency (CCE) of QBHR structure. Finally, under the same correlated color temperature (CCT) of 3640 K, the luminous efficacy and CCE enhance by 14.2% and 19.5% using the QBHR structure, respectively. In addition, the QBHR structure shows better stability than the QP structure after aging for 387.75 h. In brief, the QBHR structure shows an effective and practical packaging method to produce high-performance WLEDs.

中文翻译：

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使用量子点/氮化硼混合反射结构增强白光发光二极管的光学性能


量子点（QD）由于其优异的发光特性，通常与荧光粉一起使用以获得白光发光二极管（WLED）。为了改善照明效果，量子点层和荧光粉层应该分开，以减少重吸收损失并增强量子点稳定性。在本研究中，基于分离结构，提出了一种量子点/氮化硼混合反射（QBHR）结构来增强WLED的光学性能。 QD 通过静电方式粘合在氮化硼 (BN) 颗粒上，随后将其复合颗粒与有机硅混合，通过旋涂工艺进行 LED 封装。通过控制复合颗粒的浓度或离心速度，可以轻松地控制QBHR结构的性能。分析了不同厚度的QBHR结构的漫反射率和光致发光（PL）强度。在WLED应用远程荧光粉层时，QBHR结构的器件的发光效率随着荧光粉浓度的增加而增加，大于QD/聚二甲基硅氧烷（QP）结构的发光效率。这可能是由于散射BN颗粒的光提取能力和QBHR结构的高颜色转换效率（CCE）造成的。最后，在3640 K的相同相关色温（CCT）下，使用QBHR结构的发光效率和CCE分别提高了14.2%和19.5%。此外，老化387.75 h后，QBHR结构比QP结构表现出更好的稳定性。简而言之，QBHR 结构展示了一种生产高性能 WLED 的有效且实用的封装方法。