Eco-friendly Ag–In–Ga–S (AIGS) quantum dots (QDs) are potential alternatives in white light-emitting diodes (WLEDs) due to their high photoluminescence quantum yield (PLQY) and tunable emission. The conventional stacked-film structure using multicomponent QDs suppresses reabsorption losses among different color QDs, but inevitably introduces interfacial optical losses and manufacturing complexity and cost. In this study, a single color-conversion blended film with uniform and excellent luminescence is fabricated using high-PLQY red-emitting (85%) and green-emitting (91%) AIGS QDs simultaneously incorporated into a PMMA matrix. This deliberately utilizes reabsorption governed by the relative ratio between red and green QDs rather than solely suppressing it, thereby eliminating interfacial losses and enhancing luminance, which results in higher photoluminescence emission while maintaining a nearly identical low blue-light transmittance. Furthermore, the blended-film WLED fabricated by integrating the blended film with a blue LED chip exhibited a higher luminance (532.3 cd/m 2 ), representing a greater than 25-fold increase over the conventional stacked-film device (21.0 cd/m 2 ). The blended-film WLED achieved CIE chromaticity coordinates of (0.31, 0.32) and a color rendering index (CRI) of 87.3. The study provides a better understanding of reabsorption in single-layer multicolor QD films and promotes the development of simple and efficient I–III–VI QD backlight films for white-light display applications.
Luo et al. (Sat,) studied this question.