Very Low Degree of Energetic Disorder as the Origin of High Mobility in an n‐channel Polymer Semiconductor |
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Authors: | Mario Caironi Matt Bird Daniele Fazzi Zhihua Chen Riccardo Di Pietro Christopher Newman Antonio Facchetti Henning Sirringhaus |
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Affiliation: | 1. Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK;2. Center for Nano Science and Technology @ PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy;3. Polyera Corporation, 8045 Lamon Avenue, Skokie, Illinois 60077, USA |
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Abstract: | Charge transport is investigated in high‐mobility n‐channel organic field‐effect transistors (OFETs) based on poly{N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (P(NDI2OD‐T2), Polyera ActivInk? N2200) with variable‐temperature electrical measurements and charge‐modulation spectroscopy. Results indicate an unusually uniform energetic landscape of sites for charge‐carrier transport along the channel of the transistor as the main reason for the observed high‐electron mobility. Consistent with a lateral field‐independent transport at temperatures down to 10 K, the reorganization energy is proposed to play an important role in determining the activation energy for the mobility. Quantum chemical calculations, which show an efficient electronic coupling between adjacent units and a reorganization energy of a few hundred meV, are consistent with these findings. |
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Keywords: | organic field‐effect transistors organic semiconductors organic electronics charge transport conjugated polymers |
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