Quantum dots (QDs) are promising materials for various optoelectronic applications. However, the efficiency of QD white light-emitting diodes (QD-white-LEDs) is not at the desired level, particularly when the QD concentration in the silicone matrix is high and the corresponding mechanism has not been fully elucidated. In this study, we experimentally and theoretically investigated the aggregation-induced scattering (AIS) effect of QDs in silicone and unraveled the origin of low efficiency for QD-white-LED devices. Three-dimensional finite-difference time domain and ray tracing simulations were carried out to establish the AIS model for QDs. Results indicate that the AIS effect is stronger for higher QD concentrations and leads to a larger effective aggregate size (EAS), which was confirmed by comparing with the experimental results of QD-silicone films. Furthermore, we found that the AIS effect causes a significant reduction in the radiant efficiencies of QD-white-LEDs when the EAS exceeds 50 particles, which is validated by fabricated devices. According to the spectral energy analysis, the low efficiency of QD-white-LEDs can be attributed to a strong AIS effect at high QD concentrations, causing severe backscattering and reabsorption loss. This study is also important for nondestructive testing the degree of aggregation demonstrated by QDs in a silicone matrix and for precisely modeling QD-white-LEDs.

中文翻译：

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从聚集引起的散射效应的角度揭示量子点白光发光二极管低光效率的起源

量子点（QD）是用于各种光电应用的有前途的材料。但是，QD白光发光二极管（QD-white-LEDs）的效率未达到期望的水平，尤其是当有机硅基质中的QD浓度高且相应机理尚未完全阐明时。在这项研究中，我们从实验和理论上研究了有机硅中量子点的聚集诱导散射（AIS）效应，并阐明了量子点白光LED器件效率低下的根源。进行了三维时域有限差分和射线追踪仿真，建立了量子点的AIS模型。结果表明，对于更高的QD浓度，AIS效应更强，并导致更大的有效骨料尺寸（EAS），与量子点有机硅薄膜的实验结果比较，证实了这一点。此外，我们发现，当EAS超过50个粒子时，AIS效应会导致QD白光LED的辐射效率显着降低，这已通过装配式设备进行了验证。根据光谱能量分析，QD白光LED的低效率可归因于在高QD浓度下的强AIS效应，从而导致严重的反向散射和重吸收损失。这项研究对于无损检测有机硅基质中QD所显示的聚集程度以及精确建模QD-white-LED也是重要的。根据光谱能量分析，QD白光LED的低效率可归因于在高QD浓度下的强AIS效应，从而导致严重的反向散射和重吸收损失。这项研究对于无损检测有机硅基质中QD所显示的聚集程度以及精确建模QD-white-LED也是重要的。根据光谱能量分析，QD白光LED的低效率可归因于在高QD浓度下的强AIS效应，从而导致严重的反向散射和重吸收损失。这项研究对于无损测试有机硅基质中QD所显示的聚集程度以及精确建模QD-white-LED也是重要的。