Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 10: Organic semiconductors

HL 10.2: Talk

Monday, March 26, 2007, 15:00–15:15, H14

Electronic transport in polypyrrole thin films — •Thomas Heinzel and Cesar Bof Bufon — Institut für Physik der kondensierten Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf

We demonstrate that polypyrrole (PPy) films can be prepareded in lithographically defined patterns by vapor-phase polymerization. This technique allows the preparation of the PPy thin films (thicknesses between 6 nm and 170 nm) with low roughness onto a processed silicon substrate.[1]

The PPy thin films form granular systems, where the grains are separated by barriers which contain a certain level of dopants. The system shows an electronic transport strongly influenced by Coulomb interactions. The temperature dependence of the differential conductance exhibit an Efros-Shklovskii like hopping. The localization length was observed to depend on the applied electric field.

The PPy films can be used as an oxygen detectors. In addition, the operation of a PPy thin-film field-effect transistor at room temperature is demonstrated. Transport measurements indicate that the device works as Schottky barrier-type field-effect transistor.[1]

[1] C. Bof Bufon and T. heinzel, Appl. Phys. Lett. 89, 012104 (2006).