Over the past three decades, significant research efforts have focused on improving the charge carrier mobility of organic thin-film transistors (OTFTs). In recent years, a commonly observed nonlinearity in OTFT current–voltage characteristics, known as the “kink” or “double slope,” has led to widespread mobility overestimations, contaminating the relevant literature. Here, published data from the past 30 years is reviewed to uncover the extent of the field-effect mobility hype and identify the progress that has actually been achieved in the field of OTFTs. Present carrier-mobility-related challenges are identified, finding that reliable hole and electron mobility values of 20 and 10 cm2 V−1 s−1, respectively, have yet to be achieved. Based on the analysis, the literature is then reviewed to summarize the concepts behind the success of high-performance p-type polymers, along with the latest understanding of the design criteria that will enable further mobility enhancement in n-type polymers and small molecules, and the reasons why high carrier mobility values have been consistently produced from small molecule/polymer blend semiconductors. Overall, this review brings together important information that aids reliable OTFT data analysis, while providing guidelines for the development of next-generation organic semiconductors.
|State||Published - Sep 6 2018|
Bibliographical noteFunding Information:
This article is part of the Advanced Materials Hall of Fame article series, which recognizes the excellent contributions of leading researchers to the field of materials science. A.F.P, I.M., and T.D.A. are grateful to King Abdullah University of Science and Technology (KAUST) for financial support. The authors would like to thank the British Council (Grant No. 337323) and EPRSC (Grant No. EP/L016702/1). B.C.S. and S.S. acknowledge financial support from the Leverhulme Trust (Grant No. RF-2017-655\4) and British Council (Grant No. 337067), respectively.
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- carrier mobility
- charge transport
- contact resistance
- organic field-effect transistors
- organic semiconductors
ASJC Scopus subject areas
- Materials Science (all)
- Mechanics of Materials
- Mechanical Engineering