Conference Program - LOPE-C 2011

SCIENTIFIC CONF. | WEDNESDAY-JUNE 29, 2011
Track 5
Organic and Carbon-based Materials (04:30 pm - 06:00 pm) | LOCATION HARMONIE E / LEVEL C2
05:20 pm Flexible Transparent Conductor Based on Graphene-PEDOT/PSS Thin Film Prepared by One-step Electrolytic Exfoliation
Dr Adisorn Tuantranont,
NECTEC (ICA Lab.) , Lab Director, Thailand
Graphene is a potential candidate for flexible transparent conductor (TC) due to its excellent electrical conductivity and optical transparency. Nevertheless, the development
of graphene based TC has been hindered by the lack of efficient and low cost methods for the synthesis and large-scale high-quality thin film production. Recently reported
CVD growth on flexible copper substrates and roll-to-roll transfer process for large area graphene synthesis is considered expensive and impractical due to multi-substrate
and high temperature processing. Organic solution-based route based on chemically-reduced graphene dispersion is more attractive owing to its low cost, low temperature
processing and ease of large-scale production. However, it suffers from poor processablity because of multiple chemical processing steps. In this work, an innovative
transparent graphene-PEDOT/PSS conductive ink is developed by a simple one-step electrolytic exfoliation process instead of direct dispersion of graphene nanoflake into
PEDOT/PSS in post-processing step. The characteristics of graphene-PEDOT/PSS materials are systematically studied by varying electrolytic voltage and time. To study
optical and electrical properties, graphene-PEDOT/PSS thin film was spin coated on a glass substrate at 1000 rpm and baked at 100 ?C for 1 hour. From SEM
characterization, high-quality single crystal tetragonal graphene structures in PEDOT/PSS film is obtained at an optimum electrolytic voltage of 8 V. The transmittance is
found to decreases by around 3% while electrical conductivity increases by more than a factor of three as the voltage increases from 3 to 8 V but then becomes much less
voltage dependent when the voltage further increases. Moreover, graphene-PEDOT/PSS films synthesized at the highest voltage of 12 V and the longest time of 40 h has
shown the highest figure-of-merit of 4.77, which is more than twice higher than that of PEDOT/PSS film. The results suggest that graphene-PEDOT/PSS material prepared
by the proposed one-step synthesis is promising for transparent conductor applications.
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