Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 77: Joint Session: Organic Electronics and Photovoltaics III

HL 77.4: Talk

Thursday, March 17, 2011, 14:45–15:00, GER 38

Towards a biosensing device based on pentacene transistors — •Martin Göllner, Martin Huth, and Bert Nickel — Department für Physik und CeNS, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München, Deutschland

Organic semiconductors can be processed on flexible, biocompatible plastic substrates and offer a soft and non-toxic ambience to living cells (e.g. neurons). Therefore organic thin film transistors (OTFTs) are considered as promising candidates for the next generation of biosensing devices. However, most high mobility organic semiconductors have a limited lifetime in physiological aqueous conditions. For a stable device operation it is necessary to suppress redox reactions with the electrolyte and so called leakage currents.

For this purpose we recently used a thin alkane layer to passivate a pentacene thin film transistor, enabling the operation in an aquatic environment for many hours [1]. A transducer based on a capped OTFT should be sensitive to subtle changes of the charges at the interface to the electrolyte. Ongoing measurements indicate that it is possible to change the source-drain current of the transistor by changing the electrochemical potential of the electrolyte by a few mV. This suggests that the device should also be sensitive to the adsorption of charged molecules and the activity of cells. The sensing mechanism is discussed.

[1] M. Göllner, M. Huth, B. Nickel, Advanced Materials 22, 4350-4354 (2010)