화학공학소재연구정보센터
Journal of Vacuum Science & Technology B, Vol.27, No.2, 831-835, 2009
Self-assembled organic nanowires: A structural and electronic study
The organic conjugated polymer poly (3,3 '' '-didodecyl quarter thiophene) dissolves well in chloroform and produces a uniform film when spin cast onto an oxidized Si surface. However, the authors have determined using atomic force microscopy that when toluene is used as the solvent, the same procedure yields electrically conductive nanowires which are 5 run high, >= 20 run wide, and several microns long. Similar wires were observed after spin or drop casting the solution on Au, highly oriented pyrolitic graphite, mica, or SiO2, implying that the wires form in solution rather than during the deposition process. After the wires were deposited from solution and dried, a film which is also deposited from solution could be removed effectively without disturbing the wires by subsequent rinsing with toluene. Electrostatic force microscopy was used to study the electrical properties of the wires with 30 rim resolution after spin or drop casting them across 10 mu m wide gaps between metal contacts deposited on the Si oxide surface. With current passed between the contacts, the voltage dropped at the wire-contact interface was seen to be important, indicating a large contact resistance, but the voltage dropped at the junction of two wires was found to be very low. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3054198]