Abstract
According to the recent research, functionalized regioregular polythiophenes show fascinating properties such as high conductivity, mobility or chemosensitivity, and these properties can be controlled by functional side chains and regioselectivity, so it can be designed and synthesized for photo- and electro-material. The □-conjugated polymers can be used in plastic electronic devices such as solar cells, and the regioregular poly-3-hexylthiophene (P3HT) is a great dye for organic photovoltaic (OPV) solar cell, the divice show high efficiency, but when it was used in dye-sensitized solar cell (DSSC) the efficiency is very low, due to its poor absorbability between P3HT and TiO2. In our recent research, we find out poly-3-(butylthio)thiophene (P3BTT) has good absorption with TiO2, and its DSSC device show good efficiency, so we try to synthesize poly-3-(alkylthio)thiphenes of different side chains with varied sizes and steric hindrances via two polymerization methods, GRIM and Rieke's zinc, to find out which method and side chain gives the best efficiency of DSSC device. According to the result, poly-3-(hexylthio)thiophene (P3HTT-Zn*) prepared by Rieke's method gives the best efficiency.