Room-temperature bandlike transport and Hall effect in a high-mobility ambipolar polymer

Senanayak, Satyaprasad P and Ashar, AZ and Kanimozhi, Catherine and Patil, Satish and Narayan, KS (2015) Room-temperature bandlike transport and Hall effect in a high-mobility ambipolar polymer. In: PHYSICAL REVIEW B, 91 (11).

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Abstract

The advent of a new class of high-mobility semiconducting polymers opens up a window to address fundamental issues in electrical transport mechanism such as transport between localized states versus extended state conduction. Here, we investigate the origin of the ultralow degree of disorder (E-a similar to 16 meV) and the ``bandlike'' negative temperature (T) coefficient of the field effect electron mobility: mu(e)(FET) (T) in a high performance (mu(e)(FET) > 2.5 cm(2) V-1 s(-1)) diketopyrrolopyrrole based semiconducting polymer. Models based on the framework of mobility edge with exponential density of states are invoked to explain the trends in transport. The temperature window over which the system demonstrates delocalized transport was tuned by a systematic introduction of disorder at the transport interface. Additionally, the Hall mobility (mu(e)(Hall)) extracted from Hall voltage measurements in these devices was found to be comparable to field effect mobility (mu(e)(FET)) in the high T bandlike regime. Comprehensive studies with different combinations of dielectrics and semiconductors demonstrate the effectiveness of rationale molecular design, which emphasizes uniform-energetic landscape and low reorganization energy.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC
Additional Information:	Copy right for this article belongs to the AMER PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Keywords:	FIELD-EFFECT TRANSISTORS; HIGH CARRIER DENSITY; CONJUGATED POLYMERS; CHARGE-TRANSPORT; SEMICONDUCTING POLYMERS; ELECTRON-TRANSPORT; ORGANIC TRANSISTORS; SIDE-CHAIN; ORIGIN; INSTABILITIES
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	20 Apr 2015 11:11
Last Modified:	20 Apr 2015 11:11
URI:	http://eprints.iisc.ac.in/id/eprint/51287

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