Description:
<jats:title>Abstract</jats:title><jats:p>Organic field‐effect transistors based on aligned small molecule semiconductors have shown high charge carrier mobilities in excess of 10 cm<jats:sup>2</jats:sup> V<jats:sup>−1</jats:sup> s<jats:sup>−1</jats:sup>. This makes them a viable alternative to amorphous inorganic semiconductors especially if a high reproducibility can be achieved. Here, the optimization of high mobility organic field‐effect transistors based on the organic semiconductor 2,7‐dioctyl[1]benzothieno[3,2‐<jats:italic>b</jats:italic>] benzothiophene (C8‐BTBT) via the addition of a polymer additive to the printing solution is reported. Specifically, films and devices are compared based on solutions of the neat semiconductor and the blend with polystyrene and shear‐coated devices with excellent device characteristics and gate‐voltage‐independent mobility values reaching 12 cm<jats:sup>2</jats:sup> V<jats:sup>−1</jats:sup> s<jats:sup>−1</jats:sup> are shown, which are the highest reported values for C8‐BTBT‐based films prepared by a scalable, solution‐based process.</jats:p>