Mechanistic studies of a polarographic thin film gas sensor fabricated by MOCVD
- Argonne National Lab., IL (United States)
A novel thin film gas sensor has been fabricated by MOCVD and shown selectively sensitive to both oxidizing and reducing gases at concentrations as low as 1 ppm. The structure consists of 4 layers: a Ni/NiO base layer which acts as an oxygen source/sink, a lower RuO{sub 2} electrode, a Y{sub 2}O{sub 3} stabilized ZrO{sub 2} (YSZ) ionic electrolyte layer, and a gas-exposed upper Ru/RuO{sub 2} working electrode. Gases are detected by applying a cyclic voltage across the electrodes and measuring the current associated with electrons produced (consumed) by surface catalyzed electrochemical oxidation (reduction) reactions. The recorded voltammogram contains gas specific redox type peaks which can be matched to stored reference curves using pattern recognition methods. The two most critical material requirements for device operations are the electronic nature of the YSZ films and the electrochemical activity of the working electrode. Low growth temperatures were found beneficial for depositing YSZ films which were sufficiently electrically insulating and tonically conductive. Low oxygen background pressures were used to fabricate relatively high surface area, catalytically active Ru/RuO{sub 2} upper electrode films. The authors will discuss the effect of electrolyte thickness and electrode morphology on response time and sensitivity as well as the potential of this technology for discriminating analysis of gas mixtures.
- OSTI ID:
- 441320
- Report Number(s):
- CONF-960782-; TRN: 96:006557-0091
- Resource Relation:
- Conference: 6. international meeting on chemical sensors, Gaithersburg, MD (United States), 22-25 Jul 1996; Other Information: PBD: 1996; Related Information: Is Part Of The 6th international meeting on chemical sensors; PB: 313 p.
- Country of Publication:
- United States
- Language:
- English
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