We report the synthesis and characterization of a cross linkable, cinnamic acid functionalized, hole-transporting polyfluorene-triarylamine (PF-PTAA) copolymer. Irradiation with light induces [2 + 2] cycloaddition and renders thin films of this polymer insoluble. Spin coated films of the polymer and their light-induced cross-linking were investigated by atomic force and electron microscopy. In a proof-of principle multilayer OLED device the polymer was applied as hole transport layer (HTL) with commercially available F8BT as emitting layer (EML). Compared to the reference device without HTL we observe a significant increase in OLED performance. These results promise progress in cost-effective large area fabrication of polymer based multilayer OLEDs with superior performance.