Speaker
Description
Ph-BTBT-Cn derivatives have attracted significant attention for their good electrical performance in organic field-effect transistors (OFETs) [1]. As asymmetric small organic molecules, in thin films they exhibit a pronounced tendency toward polymorphism, including the formation of metastable phases and liquid crystalline phases upon thermal annealing [2, 3]. Although such rich thermal behaviour can be exploited for improving the electrical properties (via control of polymorphism), it can compromise the stability under thermal stress. For practical applications, it is crucial to establish a direct link between structural evolution and electrical performance during thermal annealing.
We present here a study that combines in situ Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) and electrical measurements in operando OFETs, enabling the simultaneous monitoring of structural evolution and charge transport during thermal annealing and cooling cycles. Focusing on Ph-BTBT-C12 deposited on silicon oxide as dielectric, we investigate how temperature-induced structural changes correlate with the device performance. This operando approach enables direct observation of structural transitions and their real-time impact on electrical performance. The findings highlight the critical role of polymorphism in Ph-BTBT-C12 and demonstrate the importance of simultaneous structural and electrical measurements for understanding crystal phase behaviour and optimizing organic semiconductors for high-performance electronics.
References:
[1] H. Iino, T. Usui, J. I. Hanna, Nat. Commun., 2015, 6, 6828
[2] S. Yan, D. Cornil, J. Cornil, D. Beljonne, R. P. Rivera, C. Ocal, and E. Barrena, Chem. Mater., 2024, 36, 585–595
[3] S. Hofer, A. Hofer, J. Simbrunner, M. Ramsey, M. Sterrer, A. Sanzone, L. Beverina, Y. Geerts, and R. Resel,
Journal of Physical Chemistry C, 2021, vol. 125, pp. 28 039–28