Fabrication and optical studies of epoxy-quantum-dot nanocomposites

Light emitting quantum dots were dispersed, particle-particle distance~50±8 nm, in an epoxy resin through the incorporation of ethylene glycol surfactant into the organic passivating layer of the quantum-dot nanocrystals. Evaporation of the wetting solvent enabled the ethylene glycol surfactant to incorporate into the hydrophobic layer of the semiconductor nanocrystals by interfacial interaction driven by van der Waals forces. The chemical structure effects on the degree of dispersion for the quantum-dot nanocrystals in an epoxy resin were studied. The passive optical properties of the resulting quantum-dot-epoxy nanocomposites were investigated using a light emitting diode as an excitation source. Well-dispersed nanocrystals in an epoxy showed both enhanced photo-stability and superior light emission intensity compared to the less-dispersed nanocrystals in an epoxy for 20 day evaluation.