(174e) Structure and Properties of Porous Poly(3-hexylthiophene) Gel Particles In Aqueous Dispersion

The demand for thin-film solar cells has increased significantly because modules can be inexpensively produced using scalable roll-to-roll processing techniques. We have developed aqueous dispersions of colloidal poly(3-hexylthiophene) (P3HT) gel particles that can serve as solution-processable inks for active layer materials in polymer solar cells. Bulk P3HT organogels have been emulsified into water to produce sub-micron gel particles that are stabilized with surfactant. The emulsification process produces stable dispersions of porous P3HT particles that maintain a high crystallinity, high porosity and the networked structure of the original organogel. The optical characteristics, structure and stability of the resulting gel particles have been thoroughly assessed using spectroscopy, neutron scattering, DLS and electron microscopy. It is shown that the P3HT particles retain the crystallinity and high degree of intrachain order with no evidence of doping. Simple processing is demonstrated via spray-coating of the dispersions. Thin-films have been prepared and their structure and properties have been characterized. The use of gel particle dispersions opens up a new avenue to produce thin-films for polymer solar cells and organic electronic applications while minimizing the need for post-processing.