Three-Band White Light-Emitting Diodes Based on Hybridization of Polyfluorene and Colloidal CdSe-ZnS Quantum Dots

The authors have demonstrated the hybridization of polyfluorene (PFO) polymer light-emitting diodes with CdSe-ZnS core/shell quantum dots (QDs) in different device structures. To achieve white light emission, the green and red QDs have been incorporated into the PFO as the single emissive layer. Furthermore, the whole structures were also optimized to engineer the emission spectra. Accordingly, the incorporation of QDs increased the turn-on voltage from 10 to 23 V in device with the blend ratio of PFO : green QD: red QD being 6 : 1 : 1, while the maximum brightness was dramatically decreased.