Controlling the microstructure of polymeric semiconductors and investigating its effect on charge transport
Polymeric semiconductors are gaining momentum as solution-processable semiconductors for large-area electronics. The performance of these materials as semiconductors however is strongly dependent on their processing history. Different processing conditions give rise to different microstructures, which in turn affect charge transport. Thermal processing and chemistry of the dielectric interface have a large effect on carrier mobility of semicrystalline polythiophenes. We will use synchrotron-based X-ray diffraction to correlate microstructure and charge transport in different polythiophenes. Charge transport modeling coupled with microstructural characterization indicates that in high-performance films transport is limited by the energetic distribution of intragap states and that these states are caused by defects at grain-boundaries. We will present a method to control the relative orientation of polymer grains in the substrate plane that promises to give rise to controlled trap distributions.
Salleo, A. ; Jimison, L. H.; Chabinyc, M. ; Toney, M. F. Controlling the microstructure of polymeric semiconductors and investigating its effect on charge transport. The 233rd American Chemical Society Annual Meeting; 2007 March 25-29; Chicago; IL.