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AlGaN/GaN high electron mobility transistor sensor sensitive to ammonium ions
Author(s) -
Alifragis Y.,
Volosirakis A.,
Chaniotakis N. A.,
Konstantinidis G.,
Iliopoulos E.,
Georgakilas A.
Publication year - 2007
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200674885
Subject(s) - high electron mobility transistor , materials science , transistor , ion , ammonium chloride , ammonium , detection limit , analytical chemistry (journal) , optoelectronics , ionophore , membrane , polyvinyl chloride , field effect transistor , electron mobility , chemistry , electrical engineering , chromatography , organic chemistry , composite material , biochemistry , voltage , engineering
Chemically modified Field Effect Transistor (ChemFET) sensor for ammonium (NH $ ^+_4 $ ) ions was developed from AlGaN/GaN High Electron Mobility Transistor (HEMT) structures (NH $ ^+_4 $ ‐ChemHEMT). The sensor consists of a HEMT device with non‐metallized gate, which was coated with a polyvinyl chloride (PVC) membrane enriched with ammonium ionophore (Nonactin). The AlGaN/GaN NH $ ^+_4 $ ‐ChemHEMT with gate width of 100 μm and gate length of 100 μm exhibited a constant sensitivity of 55.5 mV/pNH $ ^+_4 $ for NH $ ^+_4 $ concentration in the range from 10 –5 M to 10 –2 M. The NH $ ^+_4 $ concentration detection limit was 5.4 × 10 –6 M, which is approximately one order of magnitude lower compared to Si based insulator gate ChemFETs. The sensor exhibited also sufficiently long storage lifetime, indicating the strong adhesion of the PVC membrane to the GaN(0001) surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)