Tripling Light Conversion Efficiency of μLED Displays by Light Recycling Black Matrix

Quantum-dot color conversion film (QDCCF) with a partitioned black matrix (BM) realizes effective color generation with low crosstalk for micro-light-emitting diode (μLED) displays. However, this traditional BM seriously deteriorates light conversion efficiency (LCE) of QD converted μLED displays due to its absorption energy loss. In this paper, a novel internal and external reflective black matrix (IERBM) is proposed to improve the LCE and blue light utilization (BLU) by light recycling and reuse. Based on the IERBM structural optimization, the LCE can be respectively improved by 3.39× and 2.74× for red and green QDCC sub-pixels, and the BLU can be effectively increased by 1.11×. Accurate white balance and high color uniformity are achieved by this μLED display. Meanwhile, both the crosstalk of 1.72% and the color gamut of 89.8% Rec. 2020 are comparable with traditional absorptive BM. It is also found that the proposed IERBM has the potential to weaken μLED's sidewall effect. This work may open up a new technological route for improving the optical performance in advanced self-emissive displays.