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We have developed an inkjet process for laying down an organic semiconductor layer in organic thin‐film transistors (OTFTs). The organic semiconductor crystallinity was improved by adjusting the contact angles of the bank, the gate insulator, and the source/drain electrodes. The threshold voltage of the OTFT was controlled by means of several surface treatments of the silicon dioxide gate insulator. The OTFTs showed a high mobility of 2.5 cm2/Vs and uniform threshold voltages of −0.4 ± 0.7 V. We also fabricated a 4‐in., 80‐ppi active‐matrix organic light‐emitting diode on a glass substrate that showed good luminance uniformity and high moving picture quality.

We have fabricated Al/p-Ge(100) junctions with an ultrathin GeO 2 interfacial control layer and studied the effect of post-metallization annealing in N 2 ambience on the electrical properties from the current-voltage (I-V) characteristics. Then, the changes in the chemical bonding features with annealing were directly evaluated by using hard x-ray photo-emission spectroscopy (HAXPES). Results of these analyses showed that a GeO 2 reduction in the region near the Al/GeO 2 interface occurs after annealing at temperatures over 300 °C and that the Fermi level pinning (FLP) effect increases. This suggests that inserting a thermally and chemically stable thin layer suppresses the FLP effect at the Metal/Ge interface caused by thermal annealing. The release of this FLP effect in Al/p-Ge(100) junctions has also been demonstrated by using ultrathin N 2 sputtered hafnium nitride (HfN x ) layer instead of thermally-grown GeO 2 . And we found that the formation of a nitrogen rich region near the metal/Ge interface was an effective means of controlling the Schottky barrier height.