Optical Performance Enhancement of Quantum Dot-Based Light-Emitting Diodes Through an Optimized Remote Structure

Quantum dot (QD)-based light-emitting diodes (LEDs) always show low efficiency and unstable performance at high driving currents due to the saturation effect of QDs. In this paper, a novel remote packaging structure was proposed to reduce the saturation effect and enhance optical performances of QD-based LEDs. In the proposed packaging structure, a crater lens and an air gap between the QD-polymer film and the lens were introduced. The comparison experiments between the proposed structure and the current structures, a fully filling structure, and an air-gap structure with a spherical lens were conducted. The luminous flux increasing rates of current structures were far lower than that of the proposed packaging structure at high driving currents. Consequently, compared with the fully filling structure and the air-gap structure with the spherical lens, the proposed packaging structure has increased the luminous flux by 70.5% and 50.1% at the driving current of 800 mA. In terms of the correlated color temperature stability with the driving current, the proposed packaging structure shows the best performance. In addition, the angular color uniformity has been greatly improved by the proposed packaging structure.