Dual-Gate Organic Field-Effect Transistors as Potentiometric Sensors in Aqueous Solution
Mark-Jan Spijkman, Jakob J. Brondijk, Tom C. T. Geuns, Edsger C. P. Smits, Tobias Cramer, Francesco Zerbetto, Pablo Stoliar, Fabio Biscarini, Paul W. M. Blom, Dago M. de Leeuw, Weinheim (2010)
Buried electrodes and protection of the semiconductor with a thin passivation layer are used to yield dual-gate organic transducers. The process technology is scaled up to 150-mm wafers. The transducers are potentiometric sensors where the detection relies on measuring a shift in the threshold voltage caused by changes in the electrochemical potential at the second gate dielectric. Analytes can only be detected within the Debye screening length. The mechanism is assessed by pHmeasurements. The threshold voltage shift depends on pH as DVth ¼(Ctop/Cbottom)T58mV per pH unit, indicating that the sensitivity can be enhanced with respect to conventional ion-sensitive field-effect transistors (ISFETs) by adjusting the ratio of the top and bottom gate capacitances. Remaining challenges and opportunities are discussed.
Partners : RuG, Philips, TNO, CNR
Place of Publication : Weinheim
Date of Publication : 2010/02/25
Additional Data : ADVANCED FUNCTIONAL MATERIALS, Volume: 20 Issue: 6