Sensitive, selective and stable tin dioxide thin-films for carbon monoxide and hydrogen sensing in integrated gas sensor array applications

Rajnish K. Sharma, Philip Ching Ho Chan, Zhenan Tang, G. Yan, I. Ming Hsing, Johnny K.O. Sin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

84 Citations (Scopus)


This paper reports on the preparation, electrical and surface characterization of Cu doped tin dioxide thin-films for highly selective integrated gas sensor devices. The 3000 angstroms thin-film of 0.16 wt.% copper doped tin dioxide was deposited by reactive R.F. sputtering at room temperature and followed by 10 angstroms Pt on top of Cu doped tin dioxide thin-film (SnO2-Cu/Pt). In another batch, the 100 angstroms SiO2thin-film was deposited on top of the SnO2-Cu/Pt thin-film structure (SnO2-Cu/Pt/SiO2). The electrical response of these thin-films was investigated for CO and H2gases at different temperatures and gas concentrations. The device with the SnO2-Cu/Pt thin-film, showed excellent electrical response towards CO gas and device with SnO2-Cu/Pt/SiO2thin-film showed response towards hydrogen only. The SiO2thin-film prevents the diffusion of CO gas and only hydrogen gas diffuse through silicon dioxide layer. Using thin-films structure SnO2-Cu/Pt and SnO2-Cu/Pt/SiO2, a highly selective sensor device for CO and H2gas was fabricated. The surface characterization of these thin-films was performed using scanning electron microscopy (SEM) and X-ray photoemission spectroscopy (XPS) techniques. The SEM picture showed that surface structure of the SnO2thin-film improved by copper doping.
Original languageEnglish
Pages (from-to)160-166
Number of pages7
JournalSensors and Actuators, B: Chemical
Issue number2
Publication statusPublished - 25 Jan 2001
Externally publishedYes

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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