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Mercury‐Mediated Organic Semiconductor Surface Doping Monitored by Electrolyte‐Gated Field‐Effect Transistors
Author(s) -
Zhang Qiaoming,
Leonardi Francesca,
Casalini Stefano,
MasTorrent Marta
Publication year - 2017
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.201703899
Subject(s) - materials science , organic field effect transistor , doping , semiconductor , optoelectronics , electrolyte , organic semiconductor , transistor , field effect transistor , nanotechnology , dielectric , electrode , voltage , electrical engineering , chemistry , engineering
Surface doping allows tuning the electronic structure of semiconductors at near‐surface regime and is normally accomplished through the deposition of an ultrathin layer on top or below the host material. Surface doping is particularly appealing in organic field‐effect transistors (OFETs) where charge transport takes place at the first monolayers close to the dielectric surface. However, due to fabrication restrictions that OFET architecture imparts, this is extremely challenging. Here, it is demonstrated that mercury cations, Hg 2+ , can be exploited to control doping levels at the top surface of a thin film of a p‐type organic semiconductor blended with polystyrene. Electrolyte‐ or water‐gated field‐effect transistors, which have its conductive channel at the top surface of the organic thin film, turn out to be a powerful tool for monitoring the process. A positive shift of the threshold voltage is observed in the devices upon Hg 2+ exposure. Remarkably, this interaction has been proved to be specific to Hg 2+ with respect to other divalent cations and sensitive down to nanomolar concentrations. Hence, this work also opens new perspectives for employing organic electronic transducers in portable sensors for the detection of an extremely harmful water pollutant without the need of using specific receptors.