Enhancing Heat Dissipation of Quantum Dots in High-Power White LEDs by Thermally Conductive Composites Annular Fins

In this work, QDs/hBNs/silicone annular fins (QDs-AF) are proposed as a new type of packaging structure to establish rapid heat dissipation pathways between QDs and heat sink. The QDs-AF structure was firstly designed based on commercial LEDs modules. Then, the annular fin materials including QDs, thermally conductive hBN platelets (hBNs), and silicone were determined by balancing the tradeoff of optical and thermal performances. Finally, the optimal structure of QDs-AF was obtained through thermal simulation by changing the values of fin thicknesses of different initial QDs-AF structures. According to the optimal QDs-AF structure with 4 fins and fin thickness of 0.28 mm, we fabricated the QDs-AF and its WLEDs. Compared with QDs-WLEDs, the maximum surface working temperature of QDs-AF-WLEDs was reduced by 20 °C at 1000 mA. In addition, the QDs-AF-WLEDs showed an excellent optical performance with a high color rendering index of 90.3 and a high luminous efficiency of 124.1 lm $\text{W}^{-1}$ . The application of QDs-AF in WLEDs is a new and significant method to achieve a lower working temperature and protect QDs from thermal quenching in WLEDs.