Flexible optoelectronic device with polymer based electrode on hybrimer substrate — Impact of the bending on the interfacial processes

In this study, novel flexible organic light-emitting diode structure (f-OLED) hybrimer/polymer/metal/polymer/emissive layer/metal was proposed. We studied the effect of the mechanical bending on its electro-optical behavior. The device contains polymeric based anode PEDOT:PSS/Au/PEDOT:PSS, where the conductive polymer was spray deposited on preliminary UV exposed hybrimer surface. It was found enhancement of the film's uniformity and adhesion due to this treatment. Furthermore, due to the favorable mechanical properties of the substrate and polymeric anode, improved f-OLED performance was observed, compared to the available devices. Degradation of less than 15% after 100 bending cycles and less than 32% after 1000 was achieved for the current-brightness-voltage characteristics. The results were explained by the stability of the PEDOT:PSS morpholog. Interfacial processes were analyzed, based on the assumption for interfacial barrier variation at bending, which was confirmed by AFM anode topography and capacitance measurements. The nanoscale scanning showed continuous, crack-free polymer surface with roughness lower than 20nm after bending. We concluded that the combination substrate/anode could be reason for the small bending impact on the interfacial processes.