Charge Trapping at the Dielectric of Organic Transistors Visualized in Real Time and Space


  • We thank H. R. J. ter Veen of Calipso BV for performing LEIS measurements and P. A. van Hal, A. J. G. Mank and R. Coehoorn for the stimulating discussions. The authors gratefully acknowledge financial support from the EC (Project PolyApply IST-IP-507143). This research is supported by the Dutch Technology Foundation STW, applied science division of NWO and the Technology Program of the Ministry of Economic Affairs.


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Scanning Kelvin probe microscopy demonstrates that water-induced charge trapping at the SiO2 dielectric – visualized in real time and space – is responsible for the commonly observed gate-bias-induced threshold-voltage shift in organic field-effect transistors. When a bias is applied to the electrodes, charges are injected onto the SiO2 (see background of the figure). When the contacts are grounded, the charges are released again (foreground picture).