Surface modification of conjugated polymers: an application of near-field optical microscopy in sub-micron photochemistry

The near-field optical microscope (NSOM) was used to modify the optical properties of conjugated polymer, DP-PTV. With high nearfield intensity, the tapered fiber tip induces photo-oxidation on the polymer surface. This reaction causes a reduction in the optical absorbance of DP-PTV. By lowering the near-field intensity, NSOM reads the change in absorption images subsequently. These processes provide a new method to map the two dimensional near-field intensity distribution. In addition, lithographic patterns with a resolution of 0. 1μm are also written by applying the NSOM techniques.