Surface modifications of Ga2O3 thin film sensors with Rh, Ru and Ir clusters

Semiconducting Ga2O3 thin films react with several different gases at temperatures higher than 600 degrees C changing its conductivity. These changes of conductivity are measured by using a Platinum pattern underneath the Ga2O3 surface, in this project we added on a Ga2O3 surface, which by itself shows no strong activity as oxidation catalyst, Iridium, Rhodium and Ruthenium compounds, which change the sensitivity of the used sensors. Dissolved in organic solvents, these compounds were dispensed on the surface, then - by heating - converted into oxides and metals. This thermal decomposition process led to the formation of clusters. The so formed new sensors showed a high reproducibility and stability of their gas-sensitive electrical properties. To characterize the sensors they were tested with a variety of different gases and at different temperatures. Interesting results on very low concentrations of Ethanol and Propane were found. (C) 2000 Elsevier Science S.A. All rights reserved.