Polar Organic Gate Dielectrics for Graphene Field-Effect Transistor-Based Sensor Technology

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 9; p. 2774
• Main Authors: Kam, Kevin A, Tengan, Brianne I C, Hayashi, Cody K, Ordonez, Richard C, Garmire, David G
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.08.2018; MDPI
• Subjects: Acetonitrile; Dielectrics; Dimethyl sulfoxide; Dipole moments; Electric fields; Electrical resistivity; Field effect transistors; flexible graphene-based sensor technology; Graphene; graphene field-effect transistors; Organic chemistry; Organic liquids; polar organic dielectrics; Polyethylene terephthalate; Researchers; Semiconductor devices; Sensors; Spectrum analysis; Transistors; United States > US; flexible graphene-based sensor technology; polar organic dielectrics; graphene field-effect transistors
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18092774

We have pioneered the use of liquid polar organic molecules as alternatives to rigid gate-dielectrics for the fabrication of graphene field-effect transistors. The unique high net dipole moment of various polar organic molecules allows for easy manipulation of graphene's conductivity due to the formation of an electrical double layer with a high-capacitance at the liquid and graphene interface. Here, we compare the performances of dimethyl sulfoxide (DMSO), acetonitrile, propionamide, and valeramide as polar organic liquid dielectrics in graphene field-effect transistors (GFETs). We demonstrate improved performance for a GFET with a liquid dielectric comprised of DMSO with high electron and hole mobilities of 154.0 cm²/Vs and 154.6 cm²/Vs, respectively, and a Dirac voltage <5 V.