Conformational changes and photophysical behavior in Poly[2-methoxy-5- (2′-ethyl-hexyloxy)-1,4-phenylene vinylene] Thin films cast under an electric field

Abstract

Thin films of the light emitting conjugated polymer poly[2-methoxy-5- (2′-ethyl-hexyloxy)-1,4- phenylene vinylene] (MEH-PPV) were drop cast under a high voltage DC electric field. The conformational changes and photophysical behavior were studied systematically via steady-state and time-resolved fluorescence measurements. A clear blue shift was observed in the fluorescence spectra for thin films of MEH-PPV cast under external high electric field, and this behavior is compared to low temperature fluorescence spectra. Emission polarization measurements indicate a level of alignment of the chromophoric units when films are cast within the electric field. Moreover, an emission wavelength depende..