Gas sensitivity of InP epitaxial thin layers

Abstract The resistance of n-InP epitaxial layers is shown to increase or decrease in the presence of oxidizing (O 2 , NO 2 ) or reducing (NH 3 ) gases, respectively. The magnitude of resistance variations depends on gas concentration, on InP layer thickness and on temperature. Interpretation is based on field effect mechanisms resulting from ionization of surface-chemisorbed gas molecules. Gas sensing devices are considered.