Thermal detection mechanism of SiC based hydrogen resistive gas sensors

Abstract

Silicon carbide (SiC) resistive hydrogen gas sensors have been fabricated and tested. Planar NiCr contacts were deposited on a thin 3C-SiC epitaxial film grown on thin Si wafers bonded to polycrystalline SiC substrates. At 673 K, up to a 51.75±0.04% change in sensor output current and a change in the device temperature of up to 163.1±0.4 K were demonstrated in response to 100% H2 in N2. Changes in device temperature are shown to be driven by the transfer of heat from the device to the gas, giving rise to a thermal detection mechanism. © 2006 American Institute of Physics.