High temperature oxygen sensor using a Pt-Ga2O3-Pt sandwich structure

In this paper an oxygen sensor based on Ga2O3 films was analyzed. We propose a sensor using a Pt-Ga2O3-Pt structure with a bottom Pt layer electrode and a mesh type Pt electrode atop the Ga2O3 film. Ga2O3 films were prepared by rf magnetron sputtering from a powder target using Ar as the sputtering gas. At high temperatures Ga2O3 thin films behave like an n-type semiconductor due to oxygen vacancies. Films obtained by this method have a higher electrical conductivity due to a higher oxygen vacancy concentration. The sensing characteristics were investigated at 1000degreesC. The sensor shows good sensitivity to oxygen and a response time of about 27 s.