Graphene Organic Solar Cells with Vapor Printed Poly (3,4-ethylenedioxythiophene) Hole Transporting Layers

Publication Type:

Miscellaneous

Source:

APS Meeting Abstracts, adsabs.harvard.edu (2012)

Keywords:

2012, 2013 and earlier

Abstract:

For the successful integration of graphene as a transparent conducting electrode in organic solar cells, proper energy level alignment at the
interface between the graphene and the adjacent organic layer is critical.
The role of a hole transporting layer (HTL) thus becomes more significant
due to the generally lower work function of graphene compared to ITO. A
commonly used HTL material with ITO anodes is poly(ethylenedioxythiophene)
with poly(styrenesulfone) (PSS) as the solid state dopant. However,
graphene's low surface free energy renders uniform coverage of PEDOT:PSS
challenging. Here, we introduce a novel, yet simple, vapor printing method
via oxidative chemical vapor deposition (oCVD) for creating patterned
PEDOT layers directly onto the graphene surface. Graphene electrodes were
synthesized under both LPCVD (˜300 φ/sq at ˜92%T) and APCVD (˜450 φ/sq at
˜92%T). We demonstrate that using the donor material
tetraphenyldibenzoperiflanthene (DBP) with highly efficient graphene
electrodes (without any doping) yields organic solar cells with
performances comparable to those of the ITO reference devices (η