Employing near-field scanning optical microscopy (NSOM) as a tool for interrogating a new conjugated polymer material, di-dodecyl poly(phenylene ethynylene)

A variety of optical and scanning probe techniques have been employed to gain understanding concerning the chemical species responsible for light emission in condensed phase films of di-dodecyl poly(phenylene ethynylene) (DPPE) thin films. Thermal treatment of DPPE has been found to substantially change polymer film morphology even at temperatures below the polymer glass transition (Tg). Significant changes in sample fluorescence accompany these changes in morphology. Polarization near-field scanning optical microscopy (NSOM) has been used to make quantitative measurements of polymer film order within films having undergone various thermal processing histories. Fluorescence signatures from these films follow a trend from low-energy excimer-dominated emission in disordered films to a singlet dominated exciton emission as polymer order increases. This trend has been attributed to the breaking of polymer close-associations in a high-energy glass under thermal relaxation.;Fluorescence quenching at a polymer/metal interface has been measured using fluorescence lifetime imaging (FLI) NSOM. Results indicate that nonradiative excited state quenching occurs over a very small distance scale. The technique prevents errors in measuring quenching associated with variations in total fluorescence intensity or scanning artifacts. Results indicate that fluorescence quenching may be consequential in sandwich type polymer thin films, but will have little effect on device efficiency in planar light emitting devices with line gaps on the scale of 1 micron.;Sandwich and planar devices were fabricated using DPPE. Measurements of electroluminescent spectra acquired from sandwich devices fabricated from pristine and annealed films of DPPE were compared. Electroluminescent spectra from the two sets of devices are similar, indicating that device light emission is mediated by the presence of excimer sites in both types of films. Two sets of devices with planar geometries were also fabricated using pristine and annealed DPPE films. In these samples direct high-resolution imaging of polymer light emission in fictional light emitting devices was achieved. Photoconductive response could be elicited in biased devices under conventional epi-illumination. These results were expanded to test the viability of malting high-resolution measurements on planar gap devices using NSOM as a localized illumination source.;Standard samples for NSOM probe aperture characterization were fabricated using nanosphere lithography. Small, spatially dispersed perforations in a metal film have been used to calculate the size and shape of NSOM tip apertures. Transmission NSOM images are a convolution of the perforation being imaged, and the NSOM instrument response function. By deconvolving the size of the perforation from the image, it is possible to calculate the size and shape of the NSOM tip aperture.