Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Ambipolar field-effect organic transistors based on heterostructures

For both, the fabrication of complementary logic and for light-emitting devices, ambipolar transport in field-effect transistors is a prerequisite. Ambipolar organic field-effect transistors have been demonstrated based on bilayer heterostructures.

The devices are fabricated using pentacene/ perylene-derivative or pentathiophene/ perylene-derivative bilayers. Source and drain contacts are fabricated of two different metals with high and low work function, namely Au and Mg, in order to achieve efficient hole and electron injection, respectively. Pronounced ambipolar transistor characteristics are observed over a large range of bias voltage. The electron and hole mobility in case of pentacene/ perylene-derivative is 1.2x10-2 cm2/Vs and 2x10-4 cm2/Vs, respectively. From pentathiophene/ perylene-derivative bilayer OFETs, an electron and hole mobility of 4x10-4 cm2/Vs and 1.5x10-3 cm2/Vs, respectively, could be extracted. However, no light emission could be observed in these bilayer transistor structures.

Reported by

IBM Research GmbH, Zurich Research Laboratory
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