Role of osmium in the electrical transport mechanism of polycrystalline tin oxide thin films

Undoped and Os-doped SnO2 thin films have been deposited by the sol-gel method. Their electrical properties have been investigated by resistivity and Hall effect measurements in order to understand the role of Os in the electrical transport mechanism. The measurements have been carried out in 100-500 K temperature range both in a vacuum and in air. The experimental results have been analyzed according to the grain-boundary scattering mechanism and they have been used to explain the response toward CH4 of the Os-doped SnO2 thin-film-based gas sensors.