Gas sensors based on catalytic metal-gate field-effect devices

Abstract

The properties of gas-sensitive semiconductor devices with catalytic metal gates are reviewed, with emphasis on field-effect structures sensitive to hydrogen-containing molecules like H 2, NH 3, H 2S, alcohols, ethylene etc. A brief review of some of the developed device structures are given. The principles of hydrogen sensors with Pd gates are described in some detail. Ammonia-sensitive field-effect devices with thin catalytic metal gates are discussed. Applications of gas-sensitive field-effect devices for studies of catalytic reactions together with electron spectroscopy in UHV systems, for medical diagnosis, in leak detectors and as biosensors are reviewed.