TY - JOUR
T1 - Hall Effect in Polycrystalline Organic Semiconductors
T2 - The Effect of Grain Boundaries
AU - Choi, Hyun Ho
AU - Paterson, Alexandra F.
AU - Fusella, Michael A.
AU - Panidi, Julianna
AU - Solomeshch, Olga
AU - Tessler, Nir
AU - Heeney, Martin
AU - Cho, Kilwon
AU - Anthopoulos, Thomas D.
AU - Rand, Barry P.
AU - Podzorov, Vitaly
N1 - Funding Information:
The authors are grateful to the following programs for the financial support of this work. V.P. and H.H.C. acknowledge support from the National Science Foundation under the grant ECCS-1806363 and the Rutgers Energy Institute (REI). K.C. and H.H.C. acknowledge support from the Center for Advanced Soft-Electronics at Pohang University of Science and Technology funded by the Republic of Korea's Ministry of Science, ICT and Future Planning as Global Frontier Project (CASE-2011-0031628). M.A.F. and B.P.R. acknowledge support from the National Science Foundation Award No. ECCS-1709222. A.F.P., J.P., M.H., and T.D.A. acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) (Grant No. EP/G037515/1) and from the European Research Council (ERC) AMPRO Project No. 280221. T.D.A. and A.F.P. acknowledge the support from King Abdullah University of Science and Technology (KAUST). O.S. acknowledge the support of the Center for Absorption in Science of the Ministry of Immigrant Absorption in Israel under the framework of the KAMEA Program.
Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Highly crystalline thin films in organic semiconductors are important for applications in high-performance organic optoelectronics. Here, the effect of grain boundaries on the Hall effect and charge transport properties of organic transistors based on two exemplary benchmark systems is elucidated: (1) solution-processed blends of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) small molecule and indacenodithiophene-benzothiadiazole (C16IDT-BT) conjugated polymer, and (2) large-area vacuum evaporated polycrystalline thin films of rubrene (C42H28). It is discovered that, despite the high field-effect mobilities of up to 6 cm2 V−1 s−1 and the evidence of a delocalized band-like charge transport, the Hall effect in polycrystalline organic transistors is systematically and significantly underdeveloped, with the carrier coherence factor α < 1 (i.e., yields an underestimated Hall mobility and an overestimated carrier density). A model based on capacitively charged grain boundaries explaining this unusual behavior is described. This work significantly advances the understanding of magneto-transport properties of organic semiconductor thin films.
AB - Highly crystalline thin films in organic semiconductors are important for applications in high-performance organic optoelectronics. Here, the effect of grain boundaries on the Hall effect and charge transport properties of organic transistors based on two exemplary benchmark systems is elucidated: (1) solution-processed blends of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) small molecule and indacenodithiophene-benzothiadiazole (C16IDT-BT) conjugated polymer, and (2) large-area vacuum evaporated polycrystalline thin films of rubrene (C42H28). It is discovered that, despite the high field-effect mobilities of up to 6 cm2 V−1 s−1 and the evidence of a delocalized band-like charge transport, the Hall effect in polycrystalline organic transistors is systematically and significantly underdeveloped, with the carrier coherence factor α < 1 (i.e., yields an underestimated Hall mobility and an overestimated carrier density). A model based on capacitively charged grain boundaries explaining this unusual behavior is described. This work significantly advances the understanding of magneto-transport properties of organic semiconductor thin films.
KW - charge transport
KW - hall effect
KW - mobility
KW - organic field-effect transistors (OFETs)
KW - organic semiconductors
KW - organic thin-film transistors (OTFTs)
KW - polycrystalline films
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U2 - 10.1002/adfm.201903617
DO - 10.1002/adfm.201903617
M3 - Article
AN - SCOPUS:85068797626
SN - 1616-301X
VL - 30
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 20
M1 - 1903617
ER -