Self-Assembled, Millimeter-Sized TIPS-Pentacene Spherulites Grown on Partially Crosslinked Polymer Gate Dielectric

Abstract

Here, a highly crystalline and self-assembled 6,13-bis(triisopropylsilyleth ynyl) pentacene (TIPS-Pentacene) thin films formed by simple spin-coating for the fabrication of high-performance solution-processed organic field-effect transistors (OFETs) are reported. Rather than using semiconducting organic small-molecule-insulating polymer blends for an active layer of an organic transistor, TIPS-Pentacene organic semiconductor is separately self-assembled on partially crosslinked poly-4-vinylphenol:poly(melamine-co-formaldehyde) (PVP:PMF) gate dielectric, which results in a vertically segregated semiconductor-dielectric film with millimeter-sized spherulite-crystalline morphology of TIPS-Pentacene. The structural and electrical properties of TIPS-Pentacene/PVP:PMF films have been studied using a combination of polarized optical microscopy, atomic force microscopy, 2D-grazing incidence wide-angle X-ray scattering, and secondary ion mass spectrometry. It is finally demonstrated a high-performance OFETs with a maximum hole mobility of 3.40 cm(2) V-1 s(-1) which is, to the best of our knowledge, one of the highest mobility values for TIPS-Pentacene OFETs fabricated using a conventional solution process. It is expected that this new deposition method would be applicable to other small molecular semiconductor-curable polymer gate dielectric systems for high-performance organic electronic applications.