Metal Nanoclusters/Polyvinyl Alcohol Composite Films as the Alternatives for Fabricating Remote-Type White Light-Emitting Diodes

Packing luminescent metal nanoclusters (MNCs) into polymers and fabricating novel MNCs/polymer composite materials is effective in obtaining high-performance light-emitting diodes (LEDs). Herein, water soluble Cu and Au nanoclusters are encapsulated in polyvinyl alcohol (PVA) by a casting method. The obtained MNCs/PVA composite films are highly emissive with triple primary colors, and inherit the merits of PVA, such as transparency, flexibility, machinability, stability and self-healing ability. By employing the MNCs/PVA composite films as down-conversions, remote type monochromic and white LEDs are fabricated. The white LEDs (WLEDs) exhibit a maximum color rendering index (CRI) of 86 with a Commission Internationale de l’Eclairage (CIE) color coordinate of (0.33,0.35). By varying the three MNCs/PVA film arrangement, the correlated color temperature (CCT) of the WLEDs is tuned from 5582 to 9490 K, which signifies the possibility of MNCs/PVA as alternative light-emitting materials for advanced illumination and display in the future.