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Herein, the integration of solution-processed polymer thin-film transistors (TFTs) that were fabricated using selective wettability through ultraviolet (UV) exposure into a reflective liquid crystal display is demonstrated. From the experimental results of energy-dispersive spectroscopy, the composition of carbon and fluorine enhancing the hydrophobicity in the polymer chains was found to play a critical role in the wetting selectivity upon UV exposure. The polymer TFTs fabricated through the wettability-patterning process exhibited long-term stability and reliability. This wetting-selectivity-based patterning technique will be useful for constructing different types of solution-processed electronic and optoelectronic devices.

This brief reports a flexible active-matrix organic light-emitting diode display based on a poly-Si thin-film transistor (TFT) backplane. The p-channel poly-Si TFTs on metal foil exhibited a maximum field-effect mobility of 86.1 cm/sup 2//Vs, threshold voltage of 3.5 V, gate voltage swing of 0.8 V/dec, and the minimum off current of 10/sup -12/ A//spl mu/m at V/sub ds/=-0.1 V. A 4.1-in active-matrix backplane was fabricated with the poly-Si TFT with a conventional pixel circuit consisting of 2 TFTs and one capacitor. The scan driver circuits with PMOS were integrated on the flexible metal foil. The top emission, organic light emitting display having a brightness of 100 cd/m/sup 2/.

The photochromic properties of sputtered amorphous tungsten oxide (a-WO3−x) films have been studied. The a-WO3−x films, prepared under different oxygen partial pressures, were irradiated with ultraviolet (UV) light at room temperature, and the transmission decrease of the films was measured. We used ellipsometry for the first time with and without UV irradiation to extract the optical indices n and k of magnetron direct-current sputtered films in the VIS/IR wavelength region. We have applied for the first time the Cauchy–Lorentz model for simulating the photochromic properties of the irradiated a-WO3−x films. The results are consistent with previous reports showing that oxygen deficiency is very important in determining the photochromic properties of the a-WO3−x films.

Sol-gel processing was used to dope photochromic dyes into three matrices: metal alkoxide, metal alkoxide-polymer, and pure polymeric materials. The films on silicon and quartz substrates were examined, with and without ultraviolet (UV) irradiation, by ellipsometry, UV-visible transmission spectroscopy, and Fourier transform infrared (FTIR) transmission spectroscopy. Variable angle spectroscopic ellipsometry (VASE) data were analyzed for film thickness and optical constants, and in some cases thickness nonuniformity. A modified Cauchy and a combined Cauchy–Lorentz model were used to fit the unirradiated and irradiated film optical constants, respectively. The optical constants of the films showed significant changes upon irradiation. This means that the absorption coefficient and hence the emissivity of the films is being modulated with UV irradiation. The VASE-fitted thicknesses of the films were in the range of 1–6 μm. In the FTIR spectra, the spiropyran doped samples have shown IR transmission changes ...

— A full-color 12.1-in.WXGA active-matrix organic-light-emitting-diode (AMOLED) display was, for the first time, demonstrated using indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs) as an active-matrix backplane. It was found that the fabricated AMOLED display did not suffer from the well-known pixel non-uniformity in luminance, even though the simple structure consisting of two transistors and one capacitor was adopted as the unit pixel circuit, which was attributed to the amorphous nature of IGZO semiconductors. The n-channel a-IGZO TFTs exhibited a field-effect mobility of 17 cm2/V-sec, threshold voltage of 1.1 V, on/off ratio >109, and subthreshold gate swing of 0.28 V/dec. The AMOLED display with a-IGZO TFT array is promising for large-sized applications such as notebook PCs and HDTVs because the a-IGZO semiconductor can be deposited on large glass substrates (larger than Gen 7) using the conventional sputtering system.