Electrical and optical properties of Al-doped ITO thin films

The electrical and the optical properties of Al-doped ITO films deposited by using an rf-magnetron sputtering method on Corning glass and plastic (PET and PEN) substrates are investigated. Films deposited on Corning glass show a resistivity that continuously dereases with reducing distance d(st) between the substrate and the target clue to the improved mobility. On the other hand, in the case of the films deposited on plastic substrates, the resistivity increases with decreasing d(st) in a range of small d(st). The optical bandgap of the films deposited on plastic substrates is observed to be smaller than that of the films deposited on Corning glass. Films deposited on Corning glass change from microcrystalline to amorphous with increasing distance. On the other hand, in films deposited on the plastic substrate, the XRD peak in the (400) plane is observed even at a large distance between the substrate and the target. The transmittance of the Film deposited on a PEN substrate is found to be comparable to that of the film deposited on Corning glass.