A theoretical model for the radially dependent effective piezoelectric coefficient and corresponding piezoelectric potential in intrinsic ZnO nanowires (NWs)/nanotubes (NTs) is presented. Substrate-bound ZnO structures oriented along the c-axis with diameters of 100–5000 nm (NWs) and inner diameters of 100–900 nm (NTs; fixed outer diameter, 1000 nm) were examined using finite element method analysis. The piezoelectric potential depended nonlinearly on the NT/NW size, which we explain using the effective piezoelectric coefficient and peak piezoelectric potentials. We propose that this coefficient can be used to judge the degree of enhancement of the piezoelectric potential in ZnO NWs/NTs.

Thick-film printing processes have been applied for preparing a carbon nanotube field emission display (c-FED), which has a strong cost advantage for large-size flat panel display. For practical display applications, two types of the gated cathode structure named the normal-gate cathode and the under-gate cathode have been developed and improved. The normal-gate and the under-gate cathode structures have the driving voltages of ±35 V and ±65 V, respectively. The 5" c-FED panel with the normal-gate cathode and the 7" c-FED panel with the under-gate cathode were successfully implemented and excellent full-color video images were obtained.

Visible laser irradiation on molybdenum field emission arrays (Mo–FEAs) was performed as one efficient cleaning method in order to etch off any unnecessary oxidation layers on the FEA surface. Scanning electron microscopy and high-resolution transmission electron microscopy showed clear removal of ultrathin MoO oxide layers at the emitter edge through a photoinduced thermal process. A sharp surface morphology of the emitter tips was also observed due to the crystallization or thermalmigration effect during the laser exposure. The structural enhancement of the FEA was strongly confirmed by a remarkable increase of 40% in the emission current after laser exposure.

Electrophoretically deposited low voltage phosphors of FED are irradiated by electron beam from the Spindt micro tip arrays. The conditions of phosphor surface are analyzed at various conditions. Ar gas treatment is used for stabilizing the surface of ZnS:Cu,A1 and ZnGa20d:Mn with improved conditions. It is found that the electron irradiation on the phosphor seriously causes carbon effect to the phosphor surface, resulting in dark color defects on the real 4 inch FED panel. However, the contaminated phosphor surface is effectively eliminated by the gas sputtering treatment on it, and proved experimentally.

Oxidation and chemical modification of molybdenum micro tip surface have been investigated to understand the performance degradation mechanism of field emitter arrays (FEAs). Molybdenum FEAs could be easily oxidized due to their interaction with oxygen-containing species including O 2 , CO 2 , and H 2 O during cathode fabrication or thermal sealing processes of field emission displays(FEDs). During device operation, outgassing from phosphors due to electron-stimulated desorption and from other components inside a panel such as cathode, spacers, and sealant can lead to the chemical modification of the emitter surface. The oxidation and chemical modification of the emitter surface degrade the emission characteristics, resulting in the instability of an emission current, an increase of an electron extraction voltage for a given current, and lifetime reduction of the device. After the vacuum sealing and operation of the FED device, a micro tip is observed, and compared with an as-grown one by using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Chemical composition analyses of the degraded emitter surface by nano-probed Auger electron spectroscopy(AES) suggest that molybdenum micro tip is contaminated with S, In, C, and O after the device operation, where S and In seem to originate from the dissociation of phosphors by electron bombardment.