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.

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The effects of different annealing atmospheres on the chemical surface structure of HfO2 gate dielectric layers have been evaluated in terms of the improvement in the transconductance (gm), current on/off ratio (Ion/Ioff), and carrier mobility (μe) of a back-gated ZnO nanowire field-effect transistor (FET). Compared to O2 and N2 annealed HfO2-gated transistors, the H2 annealed HfO2-gated ZnO nanowire FET exhibited a higher transconductance of 1.77 × 10−7 A V−1, on/off current ratio of ∼1.2 × 104, and electron mobility of 11.90 cm2 V−1 s−1.

We present the annealing effects on nanochemistry and electrical properties in HfO2 dielectrics grown by metalorganic molecular-beam epitaxy. After the postannealing treatment of HfO2 films in the temperature range of 600–800°C, the thicknesses and chemical states of the films were examined by high-resolution transmission electron microscopy and angle-resolved x-ray photoelectron spectroscopy. By comparing the line shapes of core-level spectra for the samples with different annealing temperatures, the concentrations of SiO and Hf-silicate with high dielectric constant are found to be highest for HfO2 film annealed at 700°C. This result supports that the accumulation capacitance of the sample annealed at 700°C is not deteriorated in spite of a steep increase in interfacial layer thickness compared with that of the sample annealed at 600°C.

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The effect of electromechanical and mechanical strain was studied on amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistor regarding to the structural design of the device as well as the location from neutral plane (N.P) for bending stress. Here we show a highly reliable bending feature of the island structured (IS) device and its backplane against the mechanical strain after being subjected to an extreme tensile cyclic bending stress. The IS TFTs fabricated on polyimide (PI) substrate exhibit an pronounced bendability for an cyclic bending of 100,000 cycles with varying radii to a radius less than 2 mm with the electro-mechanical integrity. The onset of crack strain also closely corresponds to that of the electrical degradation of the device. The backplane array composed of IS TFTs clearly reveals that the island configuration remarkably reduce the bending stress accumulation on the sheets of inorganic stacked layers along to the uniaxial on plastic substrate.