Theoretical description of gas/film interaction on SnO/sub x/

Author

Zemel, J.N.

Author_Institution

Dept. of Electr. Eng., Pennsylvania Univ., Philadelphia, PA, USA

fYear

1988

fDate

6-9 June 1988

Firstpage

31

Lastpage

34

Abstract

A simple depletion model based on the creation and destruction of Schottky oxygen vacancies near the gas-solid interface is shown to adequately account for the free carrier and mobility response of the SnO/sub x/ films reported by S.C. Chang and D.B. Hicks (1986). Expressions for the relationship between the surface potential, bulk carrier concentration and the reducing gas concentration are derived using the standard semiconductor electrostatic surface model and first order kinetic equations for gas/solid interactions. The results obtained indicate that thin-film gas sensors of the SnO/sub x/ variety behave more like a homogeneous system where free carriers dominate the response than as polycrystalline aggregates dominated by mobility variations arising from potential variations at the intergrain boundaries.<>

Keywords

Schottky defects; carrier density; carrier mobility; chemical variables measurement; electric sensing devices; interface phenomena; reduction (chemical); semiconductor materials; semiconductor thin films; surface chemistry; surface electron states; surface potential; tin compounds; Schottky oxygen vacancies; SnO/sub x/; bulk carrier concentration; depletion model; first order kinetic equations; free carrier; gas/film interaction; gas/solid interactions; mobility; reducing gas concentration; semiconductor electrostatic surface model; surface potential; thin-film gas sensors; Aggregates; Chemicals; Conductors; Electrostatics; Gas detectors; Kinetic theory; Lead; Solid modeling; Temperature measurement; Temperature sensors;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensor and Actuator Workshop, 1988. Technical Digest., IEEE

Conference_Location

Hilton Head Island, SC, USA

Type

conf

DOI

10.1109/SOLSEN.1988.26426

Filename

26426