LAUSR

Quantum dots (QDs) have broad application prospects in displays such as full-color light-emitting diodes (LEDs) and micro-LEDs. However, an ultrahigh concentration of QDs is required to eliminate the pumping light for achieving high color purity, leading to significant reduction in the photoluminescence (PL) intensity of the QDs and the generation of much more heat. In this article, the PL intensity, thermal performance, and color purity of QD-LEDs were comprehensively improved by introducing a pumping-light absorber (PLA). Results indicate that the PLA packaging structure achieves a color purity that is similar to that of a conventional structure with ultrahigh QD concentration; the radiant power of blue light was reduced by 81.6% and this leads to a large shift in the color coordinates from (0.18, 0.26) to (0.20, 0.57). Moreover, the PLA packaging structure results in higher electroluminescence (EL) intensity and lower operating temperatures than the conventional structure. This is because of the higher color-conversion efficiency and partial transfer of thermal energy to the PLA layer. In particular, the EL intensity of the QD-LEDs increased by 25.1% and the steady-state temperature was reduced to 58.9 °C, which is 19.75% lower than that of a conventional structure (73.4 °C). In addition, the PLA packaging structure works equally well with ultraviolet (UV) pumping sources to achieve a higher color purity (enhancing the color gamut by 50.1% when using a 405-nm source).