Pd- and Pt-SiC Schottky diodes for detection of H2 and CH4 at high temperature

Hydrogen- and methane-sensing characteristics of Pt- and Pd-SiC Schottky diodes, fabricated on the same SiC substrate, have been compared and analyzed as a function of hydrogen partial pressure and temperature by I-V and DeltaI-t methods under steady-state and transient conditions at high temperature. The effects of the gas adsorption on the parameters such as barrier height, initial rate of gas adsorption, and gas reaction kinetics are investigated. Analysis of steady-state reaction kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diodes. (C) 2001 Elsevier Science B.V. All rights reserved.