Control of the Intrinsic Sensor Response to Volatile Organic Compounds with Fringing Electric Fields

Alex Henning, Nandhini Swaminathan, Yonathan Vaknin, Titel Jurca, Klimentiy Shimanovich, Gil Shalev, Yossi Rosenwaks

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

The ability to control surface-analyte interaction allows tailoring chemical sensor sensitivity to specific target molecules. By adjusting the bias of the shallow p-n junctions in the electrostatically formed nanowire (EFN) chemical sensor, a multiple gate transistor with an exposed top dielectric layer allows tuning of the fringing electric field strength (from 0.5 × 107 to 2.5 × 107 V/m) above the EFN surface. Herein, we report that the magnitude and distribution of this fringing electric field correlate with the intrinsic sensor response to volatile organic compounds. The local variations of the surface electric field influence the analyte-surface interaction affecting the work function of the sensor surface, assessed by Kelvin probe force microscopy on the nanometer scale. We show that the sensitivity to fixed vapor analyte concentrations can be nullified and even reversed by varying the fringing field strength, and demonstrate selectivity between ethanol and n-butylamine at room temperature using a single transistor without any extrinsic chemical modification of the exposed SiO2 surface. The results imply an electric-field-controlled analyte reaction with a dielectric surface extremely compelling for sensitivity and selectivity enhancement in chemical sensors.

Original languageEnglish
Pages (from-to)128-134
Number of pages7
JournalACS Sensors
Volume3
Issue number1
DOIs
StatePublished - 26 Jan 2018

Keywords

  • chemical sensor
  • fringing electric field
  • intrinsic sensor response
  • kelvin probe force microscopy
  • sensor selectivity
  • volatile organic compounds

ASJC Scopus subject areas

  • Bioengineering
  • Instrumentation
  • Process Chemistry and Technology
  • Fluid Flow and Transfer Processes

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