A selective H2 sensor implemented using Ga2O3 thin-films which are covered with a gas-filtering SiO2 layer
1996; Elsevier BV; Volume: 36; Issue: 1-3 Linguagem: Inglês
10.1016/s0925-4005(97)80085-8
ISSN1873-3077
AutoresM. Fleischer, Malobi Seth, C. Köhl, H. Meixner,
Tópico(s)ZnO doping and properties
ResumoN-type semiconducting Ga2O3 thin-films which are stable at high temperatures are used as a new basic material for gas sensors. This study investigates the extent to which a gas-filtering layer of compact, amorphous SiO2 is capable of modifying gas sensitivity. Using a sputtering technique and a Si target, the SiO2 layer, which typically, has thickness of 30 nm and 300 nm, is deposited onto the Ga2O3 gas sensor. It was found that sensors with this surface layer structure had an extremely high specificity for H2 when they were operated at 700°C. Other gases that were tested included CO, CO2, CH4, isobutene, ethanol, acetone, NO, NH3; variations of humidity and oxygen content were also investigated. There was a marked increase in H2-sensitivity between the modified and unmodified sensors.
Referência(s)