Thin-film transistor (TFT) backplanes fabricated by using jet printing as the only patterning method are reported. Additive and subtractive printing processes are combined to make 128×128 pixel active matrix arrays with 340μm pixel size. The semiconductor used, a regioregular polythiophene, poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene]; (PQT-12) is deposited by inkjet printing and exhibits average TFT mobility of 0.06cm2∕Vs, on/off ratios of 106, and minimal bias stress. The printed TFTs have high yield with a narrow performance distribution. The pixel design benefits from the registration accuracy of jet printing and it is shown that the electrical performance is suitable for addressing capacitive media displays.

Articles you may be interested inScintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency xray imaging properties of the solid-state SHARP sensor structure Med. Phys. 39, 7102 (2012); 10.1118/1.4760989 2 ∕ 3 in. ultrahigh-sensitivity image sensor with active-matrix high-efficiency electron emission device J. Vac. Sci. Technol. B 28, C2D11 (2010); 10.1116/1.3271163 High dynamic range active pixel sensor arrays for digital x-ray imaging using a -Si : H J. Vac. Sci. Technol. A 24, 850 (2006); 10.1116/1.2192526 X-ray detection by direct modulation of an optical probe beam-Radsensor: Progress on development for imaging applications Rev. Sci. Instrum. 75, 3995 (2004); 10.1063/1.1790055X-ray-induced recombination effects in a-Se-based x-ray photoconductors used in direct conversion x-ray sensors J.The factors determining the x-ray sensitivity of HgI 2 and PbI 2 as direct detector materials for large area matrix addressed x-ray image sensors are described, along with a model to explain their different properties. The imaging studies are made on test arrays with 512ϫ512 pixels of size 100 m. The x-ray sensitivity and spatial resolution are reported, along with measurements of the various mechanisms that influence the sensitivity, such as charge collection, x-ray absorption, fill factor, and image lag. The spatial resolution of PbI 2 decreases with increasing film thickness, but this effect is not observed in HgI 2 . The x-ray response data are used to compare the sensitivity to the theoretical values for the ionization energy and to identify the various loss mechanisms. We find that the sensitivity of HgI 2 can be explained by a few small and well characterized loss factors. This material exhibits good spatial resolution, high fill factor, and high charge collection. PbI 2 films exhibit lower sensitivity, principally attributable to a very large image lag. We propose that the x-ray response of the two materials is distinguished by their different depletion layer properties, and present a model that accounts for the sensitivity, image lag, and spatial resolution of PbI 2 .

No abstract

No abstract

A low temperature process for laser dehydrogenation and crystallization of hydrogenated amorphous silicon (a-Si:H) has been developed. This process removes hydrogen by laser irradiations at three energy steps. Studies of hydrogen out-diffusion and microstructure show that hydrogen out-diffusion depends strongly on film structure and the laser energy density. Both high quality and low leakage bottom gate polycrystalline silicon and a-Si:H thin film transistors were monolithically fabricated on the same Corning 7059 glass substrate with a maximum process temperature of only 350 °C.