High temperature Ga2O3-gas sensors and SnO2-gas sensors: a comparison

High temperature Ga2O3-gas sensors show some differences to other sensors based on other metal oxides like SnO2. Among the advantages of Ga2O3-based sensors good long-term stability, fast response and recovery times, good reproducibility, low cross sensitivity to humidity and short pre-ageing times have to be mentioned. The good stability in sulphur-containing atmospheres makes them suitable for use in domestic burner controls. On the other hand, is the high operation temperature of about 600–800°C which means that power consumption is comparably high (<1 W). The sensitivity of Ga2O3-sensors to CO and NO2 is lower compared to other metal oxide-based sensors. In this article measurements are presented in order to compare the performances of high temperature Ga2O3-gas sensors and SnO2-sensors. Electronic conductivity models are proposed explaining the above mentioned differences and recommendations for the different application areas are given.