Synthesis, Characterization And Photoelectric Properties Of Water-soluble Poly (Thiophene) Derivatives

The water-soluble polythiophene polymer is one of the widely studied and applied conjugated polyelectrolyte. Due to its combined performances of excellent optoelectronic properties and water-solubility, water-soluble polythiophene polymers have found applications in the fields of chemistry, materials science, biological science, etc.. In this thesis, the water-soluble polythiophene polymers were prepared by introducing ionic functional groups on the side chain to improve the solubility and processability for the application of water-soluble polythiophene polymers in organic solar cells.The 6-Chlorine hexyl thiophene-3-carboxylic ester (M-1) was achieved by reacting of the 3-thiophene acetic acid with 6-chloro-l-ethanol at 66 ℃, using N, N-dicyclohexyl diimide (DCC) as catalyst. The effects of different conditions on the yield of M-1 were investigated. Then, the 3-thiophene-Acetyl-Oxygen hexyl-triethyl ammonium chloride (M-2) was prepared by 6-Chlorine hexyl thiophene-3-carboxylic ester and triethylamine. Finally, the polythiophene derivatives poly(3-thiophene-acetyl-oxygen hexyl-triethyl ammonium chloride) (P-1) was synthesized by Fe(Ⅲ) catalytic polymerization.The poly(6-hexyl chloride thiophene-3-carboxylic acid ester) (P-2) was synthesized by Fe(Ⅲ) catalytic polymerization, using M-1 as the starting material. The quaternary ammonium poly(6-Chlorine hexyl thiophene-3-carboxylic ester) (P-3) was synthesized by P-2 and triethylamine.The poly(3-hexylthiophene-2,5-diyl) was synthesized by Fe(Ⅲ) catalytic polymerization. The polymers and intermediates were characterized by FT-IR and NMR. The Molecular weight and its distribution were measured by gel permeation chromatograph(GPC). The results showed that the number-average molecular weights of P-1 and P-3 were 3175 and 3042, the molecular weights of P-1 and P-3 were 4257 and 13880, with the molecular weight distributions of P-1 and P-3 were 1.34 and 4.562, respectively. The ultraviolet-visible spectra showed that the maximum absorption wavelengths of P-1 and P-3 were 361nm and 330nm, respectively. The Band gaps of P-1 and P-3 were 3.435 and 3.757. The TGA result showed that the stability of P-1 and P-3 is good and can be used for photovoltaic solar cells.The Polymer/graphene mixture solution film was prepared by the spin coating, using for the preparation of solar cell devices. The output characteristic was tested for studying the photovoltaic performance of the solar cell. The energy conversion efficiency of P-1/graphene、 P-3/graphene、P3HT/graphene film were 3.75×10-2%,4.2×10-3%,3.8×10-4% in the light of the conductivity, which can illustrate that the polymers can be used for photovoltaic materials.