Superior photoluminescence of quantum dot displays via organic-inorganic composite scatterers

Abstract

High color purity of quantum dot organic light-emitting diodes (QD-OLEDs) can be achieved by blue OLED light to stimulate pixelized green and red QDs within a color conversion layer, providing high color conversion efficiency in commercialized displays. However, enhancing external quantum efficiency (EQE) and minimizing blue light leakage remain significant challenges. To resolve these issues, we have developed an organic-inorganic composite system comprising quantum dots (QDs), liquid crystal (LC), polymer, and inorganic nanoparticles, like titanium dioxide (TiO2). The best EQE was enhanced by ∼81.9% when TiO2 of 6 wt%. More importantly, the EQE was enhanced by ∼58.6% when TiO2 of 3 wt% while TiO2 nanoparticles were well-dispersed and stable without aggregation for more than 3 days, which is crucial for preventing nozzle blockages during inkjet printing in manufacturing processes. We believe our innovative approach is promising for boosting color conversion efficiency by exciting highly concentrated green and red QDs with blue light while also overcoming inherent fabrication hurdles associated with high concentrations of inorganic scatterers.