HIGHLY TRANSPARENT AND CONDUCTIVE ZN2IN2O5 THIN-FILMS PREPARED BY RF MAGNETRON SPUTTERING

A new transparent conducting Zn2In2O5 film is demonstrated. The film was prepared by rf magnetron sputtering using binary compound targets composed of In2O3 and ZnO (with a Zn content (Zn/(Zn+In)) of 5-45 at%). The electrical properties were relatively independent of the substrate temperatures between room temperature and 350 degrees C. A resistivity of 3.9 x 10(-4) Ohm . cm and an average transmittance above 80% in the visible range were obtained for undoped Zn2In2O5 films with a thickness of about 400 nm. The spatial resistivity distribution on the substrate surface was minimal for Zn2In2O5 films. Optical measurements showed a band-gap energy of about 2.9 eV and a refractive index of about 2.4 for Zn2In2O5. It was found that the resistance of the undoped Zn2In2O5 films was more stable than that of undoped ZnO or In2O3 films in oxidizing environments at high temperatures.