A novel technique for increasing electron mobility of indium-tin-oxide transparent conducting films

Indium-tin oxide (ITO) films are used as transparent electrodes in display and other optoelectronic devices. Despite the reasonably high free electron concentration in these films, their electrical conductivities are much lower than that of metals. This is due in part to the reduced electron mobility caused by the high concentration of trapping centers created by structural defects in the ITO film. In this article, a simple technique is proposed for post-deposition treatment of ITO films to improve their properties. It has been found that exposure of ITO films to atomic-hydrogen plasma produces a significant increase in the electrical conductivity of the films. Under optimum conditions, over a three-fold increase in electrical conductivity is observed. The hydrogenation process does not affect optical transparency of the samples adversely. In fact a slight improvement over the visible range is seen. (C) 2002 Elsevier Science B.V. All rights reserved.