Emission ellipsometry as a tool for optimizing the electrosynthesis of conjugated polymers thin films

• DOI: 10.1016/j.tsf.2012.11.093
• Publication Date: 2012-12-07T10:01:55Z
• Authors: Eralci M. Therézio; Flavio Franchello; Ivan F.L. Dias; Edson Laureto; Maurício Foschini; Otávio L. Bottecchia; Henrique de Santana; José L. Duarte; Alexandre Marletta
• Keywords: 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 0104 chemical sciences

Abstract Emission ellipsometry technique was used as a tool to optimize the electrochemical synthesis of luminescent poly 24 [3-alkylthiophenes] conjugated polymers. This methodology was applied to poly[3-octylthiophene] (P3OT) films. P3OT films were synthesized by the chronocoulometry technique, using tetraethylammonium tetrafluoroborate and lithium perchlorate, as supporting electrolytes to control empirically the polymer/polymer interaction. After excitation with polarized light, a partially polarized emission from these films was observed. The polarization degree of the light emitted by the polymer was calculated by Stokes theory. Emission of polarized light is attributed to the limitation of energy transfer and/or diffusion processes of the excited carriers. These energy transfer and/or diffusion processes are dependent on the concentration and on the chemical nature of the electrolyte in the polymer film. The best condition for synthesis of P3OT films is correlated with the maximum of the polarization degree. The proposed methodology can be applied to optimize the electrochemical synthesis of luminescent conjugated polymers.