Dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) thin-film transistors with improved performance and stability

Organic thin-film transistors based on the vacuum-deposited small-molecule conjugated semiconductor dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) have been fabricated and characterized. The transistors have field-effect mobilities as large as 2 cm(2)/V s and an on/off ratio of 10(8). Owing to the large ionization potential of DNTT, the TFTs show excellent stability for periods of several months of storage in ambient air. Unipolar ring oscillators based on DNTT TFTs with a channel length of 10 mu m oscillate with a signal propagation delay as short as 7 mu sec per stage at a supply voltage of 5 V. We also show that DNTT TFTs with usefully small channel width/length ratio are able to drive blue organic LEDs to a brightness well above that required for active-matrix displays. (C) 2011 Elsevier B.V. All rights reserved.