CdSe/ZnS Nanoparticle composites with amine-functionalized polyfluorene derivatives for polymeric light-emitting diodes: synthesis, photophysical properties, and the electroluminescent performance

A series of amine-functionalized poly(9,9-dihexylfluorene) (PFH) derivatives, PFH-NH₂F39-1 (P1), PFH-NH₂F-19-1 (P2), PFH-NH₂F-9-1 (P3), and PFH-NH₂F-17-3 (P4), and PFH-NH ₂F-4-1 (P5), were developed to form organic/inorganic hybrid composites with CdSe/ZnS nanoparticle for polymeric light-emitting diodes (LEDs). The structures and purities of all desired polymers were fully characterized by ¹H and ¹³C NMR, UV-vis and photoluminescent spectroscopy, gel permeation chromatography, elemental analyses. The hybrid nanocomposites were in situ formed through these amino-functionalized polyfluorene derivatives doped with core-shell CdSe/ZnS quantum dots (QDs). The detailed characterizations of their photophysical properties revealed that rapid Förster energy transfer from the conjugated polymers to the redemitting QDs afforded an efficient red color emission. The preliminary polymeric LEDs fabrication with the configuration of ITO/DB/nanocomposites/Al achieved red emission for the in situ prepared hybrid nanocomposites. The investigation of device performance indicates that these nanocomposites are promising red light-emitting polymeric LED materials with good performance in providing excellent color purity, stability, and robustness. Such strategy provides us a platform to achieve red-emitting hybrid nanocomposites as the active materials for LEDs.