Synthesis and characterization of poly(3-octylthiophene)/single wall carbon nanotube composites for photovoltaic applications

In situ polymerization of P3OT with SWCNT is carried out in the presence of a FeCl₃ oxidant in a chloroform medium. The characterization of the composites is performed with FTIR, Raman,¹H-NMR, UV-Vis, PL spectroscopy, XRD, SEM, TEM, and conductivity measurements. The change (if any) in C=C symmetric and antisymmetric stretching frequencies in FTIR, the shift in G band frequencies in Raman, any alterations in λ_max of UV-Vis and PL spectroscopic measurements are monitored with SWCNT loading in the polymer matrix.¹H-NMR confirms the wrapping of the polymer on to the SWCNT indicating lack of mobility. The work function values and the optical band gap values also support this view. The in situ polymerization procedure of the donor polymer molecules and the acceptor carbon nanotubes has resulted in enhanced dispersibility and stability of the composites in organic solvents. However, the principal focus of the study is to understand the interaction between the polymer and the SWCNTs, as the interface plays an important role in its application in the photovoltaic cells.