Highly stable Cd free quantum dot/polymer composites and their WLED application

Abstract

We report the formation of an indium phosphide quantum dot/1-octadecene polymer composites by in situ polymerization and their improved properties in white LED (WLED) applications. The in situ polymerization process is very simple and efficient because the monomer is octadecene solvent, and hence, the composite was easily obtained. The quantum dots inside the composite are effectively passivated, and their stability is significantly improved. The WLED device with OE-6630 as an encapsulant shows an external quantum efficiency (EQE) of 160 lm W−1 and a color rendering index (CRI) of 90. Additionally, neutral (∼6000 K) and warm white light (∼3400 K) can be obtained by controlling the ratio of red-to-green quantum dots. Compared to a quantum dots-only system, the quantum dots/polymer composite shows significantly improved color rendering index (CRI) and external quantum efficiency (EQE) in the similar correlated color temperature (CCT) and color coordination. We expect that this new approach, based on our research, can be extended to many other applications.