Nanostructured Semiconducting Polymer Films with Enhanced Crystallinity and Reorientation of Crystalline Domains by Electrospray Deposition

Self‐organization of conjugated polymer such as poly(3‐hexylthiophene) (P3HT) causes directional anisotropy in the charge carrier mobility. In contrast to an edge‐on orientation formed in thin films of P3HT made by spin coating, in this study electrospray deposition rotates the orientation while producing nanopillar structures as a result of Coulombic fission and significant evaporation of solvent from the droplets. The nanostructured films are investigated by scanning electron microscopy. Due to substantial polymer–air interfaces oriented perpendicular to the substrate, P3HT molecules adopt a face‐on orientation with respect to the substrate plane that is confirmed by grazing incidence X‐ray diffraction. Additionally, enhanced crystallinity (29% increase) is confirmed by a redshift in the UV–vis absorption spectra. Because deposition by electrospray is a scalable nanomanufacturing method, these results inform the design of low‐cost device layers for large‐surface‐area applications such as light emitting diodes and photovoltaics. Electrospray deposition is used to rotate the orientation of polymer chain stacking in poly(3‐hexylthiophene) (P3HT) and produce nanopillar structures. These nanostructured films are investigated by scanning electron microscopy and grazing incidence X‐ray diffraction to reveal that the P3HT molecules adopt a face‐on orientation with respect to the substrate plane. Furthermore, enhanced crystallinity (29% increase) is confirmed by UV–vis absorption.