High-Resolution Scanning Near-Field Optical Lithography of Conjugated Polymers
Daniel Credgington, Oliver Fenwick, Ana Charas, Jorge Morgado, Klaus Suhling and Franco Cacialli, Weinheim (2010)
We report the fabrication of high-resolution nanostructures in both poly(p-phenylene vinylene), PPV, and a cross-linkable derivative of poly(9,9’-dioctylfluorene), F8, using scanning near-field optical lithography. The ability to draw complex, reproducible structures with 65000 pixels and lateral resolution below 60 nm (<λ/5) is demonstrated over areas up to 20µm × 20µm. Patterning on length-scales of this order is desirable for realising applications both in organic nanoelectronics and nanophotonics. The technique is based on the site-selective insolubilisation of a precursor polymer under exposure to the confined optical field present at the tip of an apertured near-field optical fibre probe. In the case of PPV, a leaving-group reaction is utilised to achieve insolubilisation, whereas the polyfluorene is insolubilised using a photoacid initiator to create a cross-linked network in-situ. For PPV, re-solubilisation of the features is observed at high exposure energies. This is not seen for the cross-linked F8 derivative, r F8Ox, allowing us to pattern structures up to 200 nm in height.
Partners : UCL
Place of Publication : Weinheim
Date of Publication : 2010/07/06
Additional Data : Adv. Funct. Mater. 2010, 20, 2842-2847