Graphene surface induced specific self-assembly of poly(3-hexylthiophene) for nanohybrid optoelectronics: from first-principles calculation to experimental characterizations

Abstract

We demonstrate a specific chain alignment of p-conjugated polythiophenes on the graphene monolayer via first-principles calculation and experimental characterizations. The effects of alkyl chain and thiophene backbone in poly(3-hexylthiophene) (P3HT) on the specific binding energy and molecular configuration on the graphene monolayer are independently investigated. Due to specific p-p interaction and van der Waals interaction between P3HT and graphene monolayer, two different configurations (edge-on and face-on) of P3HT are formed on the graphene, while only edge-on configuration of P3HT is found on the indium tin oxide (ITO). These behaviors are verified by using atomic force microscopy (AFM) and transmission electron microscopy (TEM). We also explore the molecular orientation of P3HT chains on the graphene using 2D grazing incidence X-ray diffraction (GIXD) to obtain molecular orientation features over a large area. Our results will provide a strategy to create next-generation polymergraphene nanohybrid optoelectronic devices.

Enhanced Vertical Charge Transport in a Semiconducting P3HT Thin Film on Single Layer Graphene

“…The 10 nm film deposited on graphene (Figure C) also shows strong (h00) alignment along z, but also exhibited a well defined (010) diffraction peak along the z axis, which is characteristic of π–π stacking perpendicular to the plane (face‐on in Figure A). This result is consistent with binding energy calculations performed between a P3HT chain and a graphene surface, which showed that face‐on orientation is favored at the surface of graphene …”

Pure and complex nanostructures using poly[bis(triiso‐propylsilylethynyl) benzodithiophene‐bis(decyltetradecyl‐thien) naphthobisthiadiazole], carbon nanotubes and reduced graphene oxide for high‐performance polymer solar cells

“…The crystallization kinetics of high‐density and low‐density polyethylenes on CNTs were also investigated by Depan et al . The induced crystallization of P3ATs onto graphenic materials was also widely reported; e.g. well‐oriented ultrathin P3HT films on graphene, a graphene oxide/P3AT mixture having semi‐spherulites, connecting the individual reduced graphene oxide (rGO) monolayers with P3HT nanowires 53 etc.…”

Efficiency above 6% in poly(3‐hexylthiophene):phenyl‐C‐butyric acid methyl ester photovoltaics via simultaneous addition of poly(3‐hexylthiophene) based grafted graphene nanosheets and hydrophobic block copolymers

“…Qu et al reported a reduced GO (rGO)‐pyrene‐PCBM composite, in which the PCBM was attached onto rGO via the non‐covalent functionalization approach and applied in P3HT:PCBM bulk heterojunction devices, affording a PCE of 3.89%. Suspensions of graphene and rGO have also been utilized to nucleate P3HT nanofibers and modify the orientation of crystals in P3HT thin films …”