Study in the porosity of the TiO2 films prepared by magnetron sputtering deposition

Nano-crystalline TiO₂ films with an anatase phase were deposited by reactive medium frequency magnetron sputtering deposition. Such TiO₂ films as anode for the dye-sensitized solar cells should be with a suitable porosity, two methods were used. One is change the tilt angle, i.e., the angle between sputtering beam direction and normal of the substrate, during film deposition. Another is regulating the total pressure during film deposition. Cross-section morphologies of SEM observation and measurements in optical property of the TiO₂ films were used to check the porosity of the deposited TiO₂ films. The result shows that increasing the tilt angle and increasing the total pressure are both effective to increase the porosity of the TiO₂ films. And the results from both checking analyses are very coincident.