TiN in work function type sensors: a stable ammonia sensitive material for room temperature operation with low humidity cross sensitivity

Bernhard Ostrick, Roland Pohle, Maximilian Fleischer, Hans Meixner

Research output: Conference article

23 Citations (Scopus)

Abstract

In this work, it was found that exposure of TiN to ammonia (400 ppb-100 ppm) in wet synthetic air at room temperature leads to a reversible decrease of ΔΦ. There is a change of the work function of -30 meV/decade of increasing ammonia concentration at room temperature. The response time (t90) to 1 ppm is ≤ 1 min. The sensitivity is a typical room temperature effect as it decreases at higher temperatures up to 100°C. The reaction has a low cross sensitivity to humidity, as - first - the sensitivity to ammonia does not depend on the relative humidity and - second - the work function change due to humidity changes is as low as -2 meV for an increase of 10% in relative humidity. The Diffuse Reflectance Infrared Fourier Transform Spectra (DRIFT-spectra) indicate that the adsorption of ammonia is correlated with a decrease of OH species on the surface. All data are compared to the gas reactions of TiO2.

Original languageEnglish
Pages (from-to)234-239
Number of pages6
JournalSensors and Actuators, B: Chemical
Volume68
Issue number1
DOIs
Publication statusPublished - aug. 25 2000
EventProceedings of Eurosensors XIII - The Hague, Neth
Duration: szept. 12 1999szept. 15 1999

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

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