Letter Jet-printed electrodes and semiconducting oligomers for elaboration of organic thin-film transistors S. Sanaur a, * , A. Whalley b , B. Alameddine c , M. Carnes b , C. Nuckolls b a Departement of Packaging and Flexible Substrate, Center for Microelectronics of Provence – Georges Charpak, Ecole Nationale Supe ´rieure des Mines de Saint-E ´ tienne, Laboratoires Morandat, impasse de la Plaine 13120, Gardanne, France b Department of Chemistry and The Nanoscience Center, Columbia University, 3000 Broadway Avenue, New York, NY 10027, USA c Chemistry Department, University of Balamand, P.O. Box 100, Tripoli, Lebanon Received 9 March 2006; received in revised form 2 May 2006; accepted 3 May 2006 Available online 9 June 2006 Abstract A new oligomer of bithiophene and substituted fluorene has been successfully synthesized, exhibiting good FET perfor- mance. Our results show that devices can be obtained from inkjetted OTFTs and elaborated by direct writing without any particular pre-patterning or self-alignment techniques. We have also demonstrated the possibility to fabricate inexpensive OTFTs by direct writing paving the way toward using inkjet printing as the key technology for such applications in plastic electronics. The ease of this technique allows charts a clear path to flexible electronics. Ó 2006 Elsevier B.V. All rights reserved. PACS: 85.30.z; 72.80.Le; 81.07.b; 73.61.Ph; 85.30.Tv Keywords: Inkjet printing; OTFT; Semiconductor molecular engineering; Gold nanoparticles; Direct writing Here we describe the direct inkjet printing of transistors that utilize a semiconducting layer formed from the oligomers of bithiophene and the substituted fluorene and source and drain electrodes formed from gold nanoparticles. Organic materials are promising candidates to make organic thin-film transistors (OTFTs) active components for the fab- rication of low-cost devices for applications such as radio frequency identity (RFID) tags [1], polymer electronics [2], and OTFT display backplanes [3]. However, the carrying out of OTFTs does not attain the low-cost expected. Inline mass produc- tion, where the global process is made in continuous by one machine as fast as possible, fills this require- ment. That is to say the integration of processes like spin-coating, photolithography, e-beam lithogra- phy, or vacuum thermal evaporation (VTE) steps [4] will become too expensive. Direct printing techniques are mentioned to be one of the key-technologies [5] to complete such plastic electronics devices. The first existing tech- nique consists of a pad printing technique in contin- uous processing [6]. The second approach is based on flexography technique which requires, as a pre- ceding step to processing, the fabrication of a solid master by photolithography [7]. The last approach 1566-1199/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.orgel.2006.05.003 * Corresponding author. Tel.: +33 4 42 50 92 74; fax: +33 4 42 51 34 22. E-mail address: sanaur@emse.fr (S. Sanaur). Organic Electronics 7 (2006) 423–427 www.elsevier.com/locate/orgel