Graphene exfoliation in the presence of semiconducting polymers for improved film homogeneity and electrical performances

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2018-01-11

00086223

Carbon

We report on the production of hybrid graphene/semiconducting polymer films in one step procedure by making use of ultrasound-assisted liquid-phase exfoliation of graphite powder in the presence of π-conjugated polymers, i.e. poly(3-hexylthiophene)
Show moreWe report on the production of hybrid graphene/semiconducting polymer films in one step procedure by making use of ultrasound-assisted liquid-phase exfoliation of graphite powder in the presence of π-conjugated polymers, i.e. poly(3-hexylthiophene) (P3HT) or poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-alt-[1,2,5]thiadiazolo-[3,4-c]pyridine] (PCDTPT). The polymers were chosen in view of their different propensity to form crystalline structures, their decoration with alkyl chains that are known to possess high affinity for the basal plane of graphene, the energy levels of their frontier orbitals which are extremely similar to the work function of graphene, and their high electrical performance when integrated in field-effect transistors (FETs). The polymers act as a dispersion-stabilizing agent and prevent the re-aggregation of the exfoliated graphene flakes, ultimately enabling the production of homogeneous bi-component dispersions. The electrical characterization of few-layer graphene/PCDTPT hybrids, when integrated as active layer in bottom-contact bottom-gate FETs, revealed an increase of the field-effect mobility compared to the π-conjugated-based pristine devices, a result which can be attributed to the joint effect of the few-layer graphene sheets and semiconducting polymers improving the charge-transport in the channel of the field-effect transistor. In particular, few-layer graphene/PCDTPT films displayed a 30-fold increase of PCDTPT's mobility if compared to pristine polymer samples. Such findings represent a step forward towards the optimization of graphene exfoliation and processing into electronic devices, as well as towards improved electrical performance in organic-based field-effect transistors.
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Elsevier

Carbon

ACL

LabEx project Nanostructures in Interaction with their Environment (ANR-11-LABX-0058_NIE)

Graphene Flagship (GA-696656)

Chimie/Matériaux

Organic semiconductors
Graphene composites
Liquid phase exfoliation
Hybrid films

Istituto per la Microelettronica e Microsistemi (IMM), CNR, via Gobetti 101, 40129 Bologna, Italy
Institut für Makromolekulare Chemie, Stefan-Meier-Straße 31, 79104 Freiburg, Germany

E2 : DSI - Département Surfaces et Interfaces

aut
crp

International