Detection mechanisms of smoke compounds on homogenous semiconductor sensor films

• Published in: Thin solid films Vol. 490; no. 1; pp. 1 - 6
• Main Authors: Kohl, D., Eberheim, A., Schieberle, P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 21.10.2005; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Gas chromatography; Gas sensor; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Tin oxide; Wood smoke; Gas chromatography; Gas sensor; Wood smoke; Tin oxide; Semiconductor materials; Films; Toluene; Combustion; Selectivity; Chromatography; High-resolution methods; Tin oxides; Hydroxyl group; Reaction mechanism; Arrays; Gas sensors; Acetone; Organic compounds
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2005.04.008

The conductivity changes of tin oxide sensor films kept at 270 °C to various organic compounds originating during the combustion of wood were investigated by HRGC/SOMMSA (high resolution gas chromatography/selective odorant measurement by multisensor array). The films show high sensitivity and selectivity to organic compounds with hydroxyl groups. Phenolic structures lead to strong conductivity increases. Exposure to toluene, furfural and acetone does not change the film conductivity. The reaction of the films to beech wood smoke is primarily due to 2-methoxyphenol and 2,6-dimethoxyphenol derivatives with para-substituted alkyl and alkenyl groups, which originate in hardwood lignia. Both types of compounds occur in relatively high concentrations during smouldering and both are sensitively detected. In spruce wood smoke only reactions to 2-methoxyphenol derivatives occur. Reaction mechanisms are discussed in some details.