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Concentration-dependent mobility in organic field-effect transistors probed by infrared spectromicroscopy of the charge density profile

A. D. Meyertholen·Z. Q. Li·D. N. Basov·M. M. Fogler·M. C. Martin·G. M. Wang·A. S. Dhoot·D. Moses·A. J. Heeger
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Abstract

We show that infrared imaging of the charge density profile in organic field-effect transistors (FETs) can probe transport characteristics which are difficult to access by conventional contact-based measurements. Specifically, we carry out experiments and modeling of infrared spectromicroscopy of poly(3-hexylthiophene) (P3HT) FETs in which charge injection is affected by a relatively low resistance of the gate insulators. We conclude that the mobility of P3HT has a power-law density dependence, which is consistent with the activated transport in disorder-induced tails of the density of states.

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A. D. Meyertholen, Z. Q. Li, D. N. Basov, M. M. Fogler, M. C. Martin, G. M. Wang, A. S. Dhoot, D. Moses, A. J. Heeger. 2007-03-19. Concentration-dependent mobility in organic field-effect transistors probed by infrared spectromicroscopy of the charge density profile. https://doi.org/10.1063/1.2745223

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