Study On Transparent Conductive Properties Of ITO Thin Films Prepared By RF Magnetron Sputtering

ITO thin films have been successfully used in displays,touch screens,and solar cells due to their excellent transparent conductive properties.However,there are still some factors and mechanisms that affect the photoelectric properties of thin films.In this paper,ITO thin films with different film thicknesses were prepared by RF magnetron sputtering in Ar/Ar+H2 atmosphere at different substrate temperatures(Ts).The films were annealed in Ar and air respectively.The influence of Ts,film thickness,H2 flux,annealing atmosphere and annealing temperature on the transparent conductive properties of the films were studied.The main results obtained are as follows:When the films are deposited in Ar atmosphere,the thickness of the ITO thin films changes little with the increase of substrate temperature.But the crystallinity gradually increases,and its preferred orientation gradually changes from the(400)plane to the(211)plane.For the transparent conductive properties,as the substrate temperature increases,the average transmittance of the films in the visible light region first increases slightly and then decreases significantly.However,the resistivity abnormally increases first and then decreases.At three substrate temperatures(RT,100 and 200?),as the film thickness increases,the crystallinity of the ITO thin films increases and the preferred orientation decreases.The resistivity shows a constant or rising trend,and the transmittance decreases.When the films are deposited in Ar+H2 atmosphere at three substrate temperatures(RT,100 and 200?),the thickness of the ITO film does not change significantly with the increasing H2 flux,but the crystallinity tends to increase.The diffraction peak of In appears at high H2 flux when the substrate temperature is 100 or 200?.For the transparent conductive properties,as the H2 flux increases,the resistivity of ITO thin films prepared at three substrate temperatures gradually decreases.The transmittance remains unchanged at first,and then suddenly decreases.Similar to the ITO film prepared in Ar atmosphere,the crystallinity of the ITO thin films prepared in Ar+H2 atmosphere increases with the increasing film thickness,and the transmittance shows a decreasing trend.However,when the Ts is 100 oC,the resistivity of the ITO thin films increases rapidly and then tends to remain stable,but it gradually decreases when the Ts is 200?.Annealing in Ar atmosphere,the crystallinity of the ITO thin film prepared in Ar and Ar+H2 atmospheres increases with the increasing annealing temperature.The resistivity decreases,and the transmittance first increases and then decreases.In contrast,the resistivity of the ITO thin films deposited in Ar atmosphere shows a more significant decrease.Annealing in air atmosphere,the crystallinity and transmittance of the ITO thin films deposited in both atmospheres increase with the annealing temperature.The resistivity of the ITO thin films deposited in Ar atmosphere decreases while the resistivity of ITO thin films deposited in Ar+H2 atmosphere increases.With the increase of annealing temperature in air atmosphere,the diffraction peak of In in the non-transparent ITO thin films deposited in high H2 flux gradually disappears.The resistivity and transmittance gradually increase.