Effect of CdSe/ZnS quantum dots on color purity and electrical properties of polyfluorene based hybrid light emitting diode

• Blue color light emitting diode based on polyfluorene-CdSe/ZnS quantum dot blend is reported.
• The color purity of blue light is enhanced by doping 25 wt.% of CdSe/ZnS quantum dots.
• The electrical properties of the device are also enhanced.
• Results are compared with 1-D photonic crystals fabricated on OLEDs.

We report enhanced color purity of hybrid organic-inorganic light emitting diode based on polyfluorene-CdSe/ZnS quanum dot (QD) blend as emissive layer. Effect on structural, optical and electrical properties of different doping concentration (0–100 wt.%) of QD in polyfluorene (PFO) was studied. Photoluminescence and electroluminescence spectra confirm the β-formation of PFO by incorporation of CdSe/ZnS QD. Photoluminescence (PL) of blend film was also compared with another method based on one dimensional photonic band gap (1D-PBG) structure that has been used for color purity. In both the cases, that is, QD doped device and 1D-PBG based structures the narrowing of PL spectra was observed. But the fabrication of QD-doped device for color purity is easier than fabricating 1D-PBG structure using multilayer dielectric coating. The present study might find application for QD based color displays, where color purity is an important requirement.

Enhanced color purity of hybrid organic-inorganic light emitting diode based on polyfluorene-CdSe/ZnS quanum dot (QD) blend as emissive layer is reported. Effect on structural, optical and electrical properties of different doping concentration (0–100 wt.%) of QD in polyfluorene (PFO) was studied. It was found that the 25% QD doped PFO device showed the high color purity (Figure 1(a)) and luminance (Figure (b)).Figure optionsDownload as PowerPoint slide