The time dependence of small-angle X-ray scattering (SAXS) curves for silver nanoparticle formation was followed in situ at a time resolution of 0.18 ms, which is 3 orders of magnitude higher than that used in previous reports (ca. 100 ms). The starting materials were silver nitrate solutions that were reacted with reducing solutions containing trisodium citrate. The SAXS analyses showed that silver nanoparticles were formed in three distinct periods from a peak diameter of ca. 0.7 nm (corresponding to the size of a Ag(13) cluster) during the nucleation and the early growth period. The Ag(13) clusters are most likely elementary clusters that agglomerate to form silver nanoparticles.

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A lack of high-mobility transistors has been one of the most crucial challenges facing the development of printable electronics. In this work, we report on the fabrication of high-mobility carbon nanotube thin-film transistors using a combination of transfer and high-speed flexographic printing techniques. Based on lithography-free nonvacuum processes, a high mobility of 157 cm2 V-1 s-1 with an ON/OFF ratio of 104 was achieved. Our ambient fabrication technique provides not only a promising platform for printed flexible devices but also demonstrates the realistic potential of low-cost manufacturing technology.

We fabricated sub-10-µm-class short-channel, top-gate carbon nanotube thin-film transistors using a flexographic printing technique, which is a high-speed printing technique that uses a flexible polymer plate. This device fabrication process is completely photolithography-free and vacuum-free as a result of the printing technique. The printing resolution was improved by using micro-flexo plates fabricated by a microprocessing technique. The fabricated device, with a channel length of 9.5 µm, exhibited a high on-current of 0.94 mA/mm. Hysteresis was suppressed by introducing a top-gate structure.

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