Aggregation and Gelation Effects on the Performance of Poly(3-hexylthiophene)/Fullerene Solar Cells

• Published in: Macromolecules Vol. 41; no. 20; pp. 7485 - 7489
• Main Authors: Huang, W. Y, Huang, P. T, Han, Y. K, Lee, C. C, Hsieh, T. L, Chang, M. Y
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 28.10.2008
• Subjects: Applied sciences; Energy; Exact sciences and technology; Natural energy; Organic polymers; Photovoltaic conversion; Physicochemistry of polymers; Properties and characterization; Solar cells. Photoelectrochemical cells; Solar energy; Solution and gel properties; Short circuit currents; Fullerene compounds; Gelation; Photoluminescence; Aromatic polymer; Physical gel; Experimental study; Fill factor; Open circuit voltage; Thin film; Photovoltaic cell; Organic solution; Binary mixture; Conjugated polymer; Thiophene derivative polymer; Optical properties; Concentration effect; Kinetics; Optical absorption
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma801368z

Poly(3-hexylthiophene) formed gels and showed liquid crystalline structures at high concentrations. The absorption properties of poly(3-hexylthiophene) showed dramatic changes during gelation, which is an indication of strong intermolecular π-electronic coupling of the ordered self-assembled poly(3-hexylthiophene) gels. The effect of conformational transitions on the photovoltaic properties of solution-processed poly(3-hexylthiophene)/fullerene blends has been studied in this Article. It is shown that the photovoltaic performance is strongly affected by gelation, which alters the morphology of the photoactive layer. Device optimization yields solar cells with a power conversion efficiency of 3.78% under standard test conditions (AM 1.5, 100 mW/cm2).