Reactive-Insulator SiC-Based Schottky Diodes as Gas Sensors

Improved silicon carbide-based Schottky diodes are undergoing development for use in detecting hydrocarbon (CxHy) and nitrogen oxide (NOx) gases at high temperatures. In comparison with gas sensors of other types, Schottky-diode gas sensors exhibit relatively high sensitivity -- an advantage for monitoring engine-exhaust emissions and hazardous gases emitted in low concentrations. SiC-based Schottky diodes can function at temperatures too high for Si-based devices; beyond the obvious advantage of a wider operating-temperature range, this opens the possibility of incorporating into sensors materials that react with CxHy and NOxat high temperatures in ways that enhance sensitivity, selectivity, and/or stability.