Controlling the architecture of chiral conjugated polymer spin-cast films

ORGN 75

Andrew Satrijo, asatrijo@mit.edu and Timothy M. Swager. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139
The performance of many conjugated polymer-based optoelectronic devices, such as light emitting diodes, is dependent on the morphology of the polymer film. However, the nature of polymer interchain interactions and aggregation in spin-cast films is still unclear. In this study, circular dichroism and absorption spectroscopy were employed to monitor the aggregation behavior of chiral poly(p-phenylenevinylene) (PPV) derivatives in solution and in spin-cast films. From one PPV, three distinct film architectures were fabricated: a disordered assembly and two chiral organizations with opposite handedness. The different packing organizations directly correlate with the spin-casting solution's degree of polymer aggregation, which can be controlled by changing the solvent. Incorporation of bulky, interlocking side groups into the PPV facilitated the assembly of ordered, chiral architectures in films spin-cast from a good solvent.