Sensitivity optimization of epitaxial graphene based gas sensors

Epitaxial 4H-SiC graphene films were fabricated and tested for sensing ambient gases. Sensitivity response to nitrogen dioxide was optimized by varying operation temperature and humidity. At elevated temperature the response was found to be -10.0 % of the resistance change when the gas mixture with NO₂ concentration of 10 parts per billion (10 ppb) was applied. Optimisation of sensitivity can be done by control and adjustment of the operation temperature and humidity level.