Fabrication of conjugated polymer nanowires by edge lithography.
This paper describes the fabrication of conjugated polymer nanowires by a three stage process: (i) spin-coating a composite film comprising alternating layers of a conjugated polymer and a sacrificial material, (ii) embedding the film in an epoxy matrix and sectioning it with an ultramicrotome (nanoskiving), and (iii) etching the sacrificial material to reveal nanowires of the conjugated polymer. A free-standing, 100-layer film of two conjugated polymers was spin-coated from orthogonal solvents: poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) from chloroform and poly(benzimidazobenzophenanthroline ladder) (BBL) from methanesulfonic acid. After sectioning the multilayer film, dissolution of the BBL with methanesulfonic acid yielded uniaxially aligned MEH-PPV nanowires with rectangular cross sections, and etching MEH-PPV with an oxygen plasma yielded BBL nanowires. The conductivity of MEH-PPV nanowires changed rapidly and reversibly by >10 (3) upon exposure to I 2 vapor. The result suggests that this technique could be used to fabricate high-surface-area structures of conducting organic nanowires for possible applications in sensing and in other fields where a high surface area in a small volume is desirable.
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Darren J
DJ
Lipomi
Ryan C
RC
Chiechi
Michael D
MD
Dickey
George M
GM
Whitesides
D001562:Benzimidazoles / Q000737:chemistry*; D004566:Electrodes; D007546:Isoquinolines / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*; D013053:Spectrophotometry; D014753:Vinyl Compounds / Q000737:chemistry*
D001562:Benzimidazoles; D007546:Isoquinolines; D011108:Polymers; D014753:Vinyl Compounds; C520682:poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene)