Substituted Polyfluorene-Based Hole Transport Layer with Tunable Solubility

We report on the synthesis and electrical characterization of polyfluorene−triarylamine-based hole transport layers (HTLs). The solubility of the HTL can be tuned by adjustment of the chemical structure without loss of the charge transport properties. Double-layer polymer light-emitting diodes are constructed with an HTL that is not soluble in toluene at room temperature, combined with a poly(p-phenylene vinylene) (PPV)-derivative-based light-emitting layer. The addition of the HTL enhances the efficiency of the PLED with 10% at higher voltages.