Transparent conductive Al-doped ZnO films for liquid crystal displays

Al-doped zinc oxide (ZnO:Al) films were applied to liquid crystal displays (LCDs) as transparent electrodes substituting indium tin oxide (ITO). While the ZnO:Al-based twisted nematic LCD cell showed similar operational behavior to ITO-based counterpart, its electro-optical (EO) and residual dc (r-dc) characteristics were somewhat improved. Capacitance-voltage relations suggested that these improved EO and r-dc characteristics of the ZnO:Al-based LCD cell are due to the substantially lower density of charge carrier trapping centers in the polyimide layer/electrode interface region, demonstrating high application potential of ZnO:Al films as transparent electrodes of LCDs.