Synthesis of Polythiophene Derivatives with Schiff Base Groups and Use as an Active Layer in Polymer Solar Cell Devices

Two kinds of Schiff bases polymers named P3TA4A and P3TA4B were prepared by the chemical oxidation method. The structures of Schiff bases polymers were determined by FT-IR and 1H NMR. The GPC result showed that the number-average molecular weight of P3TA4A and P3TA4B was 7400 g/mol and 12500 g/mol with a molecular weight distribution of 1.63 and 1.27, respectively. The cyclic voltammetry curves showed that the energy gap of P3TA4A and P3TA4B was 1.929 eV and 1.944 eV, respectively. Ultraviolet-visible spectra and Luminescence spectra showed that the maximum absorption and maximum emission wavelength of was 275 nm, 400 nm for P3TA4A and 448 nm, 451 nm for P3TA4B. The open-circuit voltage of the polymer solar devices was 3 mv and 2.5 mv, respectively. The results indicated that the Schiff bases substituents at the 3-position of polythiophenes play an important role on the photoelectric conversion efficiency of conducting polymers.