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Dual‐Gate Organic Field‐Effect Transistors as Potentiometric Sensors in Aqueous Solution
Author(s) -
Spijkman MarkJan,
Brondijk Jakob J.,
Geuns Tom C. T.,
Smits Edsger C. P.,
Cramer Tobias,
Zerbetto Francesco,
Stoliar Pablo,
Biscarini Fabio,
Blom Paul W. M.,
de Leeuw Dago M.
Publication year - 2010
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200901830
Subject(s) - materials science , passivation , potentiometric titration , optoelectronics , field effect transistor , transistor , wafer , threshold voltage , potentiometric sensor , gate dielectric , sensitivity (control systems) , aqueous solution , debye length , electrode , dielectric , analytical chemistry (journal) , voltage , ion , nanotechnology , layer (electronics) , electrical engineering , electronic engineering , chemistry , chromatography , engineering , organic chemistry
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 pH measurements. The threshold voltage shift depends on pH as Δ V th = ( C top / C bottom ) × 58 mV 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.