Effects of Sc- and Zr-doped MgO layers on electron emission and discharge characteristics of alternating-current plasma display panels

Abstract

To improve the material properties of a protective layer for alternating-current plasma display panels, a small amount of Sc or Zr was added to a conventional MgO protective layer. The electrical properties and surface characteristics of the Sc and Zr doped MgO protective layers deposited by an ion plating method were investigated. Experimental results show that the secondary electron emission coefficients of the Sc and Zr MgO protective layers are higher than those of conventional MgO protective layers, resulting in the reductions in firing voltage and address discharge delay time. To elucidate the reason for the increase in secondary electron emission, the changes in work function and energy band structure were investigated by cathodoluminescence (CL) measurement and ultraviolet photoelectron spectroscopy (UPS). The measurements show that the work functions of the Sc and Zr MgO protective layers markedly decreased in comparison with that of the conventional MgO protective layer. Experimental results reveal that the secondary electron emission has a strong correlation with the change in work function or energy band structure that is related to the defect level produced by doping, thereby resulting in changes in electrical discharge voltage and delay time. © 2014 The Japan Society of Applied Physics.