Gas-sensitive electrical properties of pure and doped semiconducting Ga2O3 thick films

The gas-sensitive electrical properties of pure Ga2O3 thick films are investigated. The influence of doping on these properties has also been studied. SnO2 was used as donator type dopand. It was found that there is an increase in the overall conductivity due to the doping up to two orders of magnitude. Despite this high conductivity, the gas sensitivity remains almost unchanged in all cases. There is no effect of the dopands on the bulk controlled oxygen sensitivity. Pure and doped Ga2O3 thick films have been proved to be reproducible and stable sensor base materials. The result forms the base for the use of screen-printed electrodes or a further reduction of the chip size for a decreased heating power consumption. (C) 1998 Elsevier Science S.A. All rights reserved.