Effect of Packaging Method on Performance of Light-Emitting Diodes With Quantum Dot Phosphor

Abstract

In this letter, remote quantum dot phosphor-converted light-emitting diodes (QD-LEDs) with air encapsulation, silicone lens, and silicone encapsulation were fabricated. The effects of different packaging methods on the optical and thermal performances of QD-LEDs were evaluated based on the experimental tests and simulation. Optical efficiency and spectral stability were tested by experiment, and the temperature was assessed by finite-element simulation and infrared thermal imager tests. It was found that the silicone encapsulation type could convert more blue light into QDs emission light due to the reabsorption of backward reflected blue light. The silicone encapsulation type showed only a 6.2% decrease in QDs emission peak intensity when the driving current varied from 50 to 500 mA, while the silicone lens type dropped by 20.4% and the air encapsulation dropped by 36.8%. It was also confirmed that the QDs temperature in silicone encapsulation was 24 °C lower than those in the air encapsulation type and the silicone lens type at driving current of 300 mA.