Preparation and characterization of transparent semiconductor RuO2–SiO2 films synthesized by sol–gel route

RuO2–SiO2 thin films with different Si/Ru molar ratios were prepared by the sol–gel method, using the hydrate ruthenium (III) chloride (RuCl3·3.5H2O) and tetraethylorthosilicate as precursors. The crystal structure, resistivity, chemical bonding configuration, transmittance, carrier concentration, and mobility of the RuO2–SiO2 films were investigated before and after annealing in N2 ambient at 400–700 °C. The resistivity of the RuO2–SiO2 films with different Si/Ru molar ratios decreased abruptly after annealing at 400–700 °C. On the other hand, RuO2 phase precipitated in the RuO2–SiO2 films with different Si/Ru molar ratios after annealing. Fourier transform infrared spectroscopy spectra indicated that the water absorption occurs for as-deposited RuO2–SiO2 films with different Si/Ru molar ratios. The transmittance of all RuO2–SiO2 films presented transmittance maximums after annealing at 700 °C. The carrier concentration and mobility of RuO2–SiO2 films are related to the Si/Ru molar ratios and the annealing temperature. This study discusses the connection among the material properties of the RuO2–SiO2 films and how they are influenced by the Si/Ru molar ratios and the annealing temperatures of RuO2–SiO2 films.