Influence of molecular weight on the spectroscopic properties of a series of well-defined poly(3-hexylthiophene) polymers

A series of five poly(3-hexylthiophene) (P3HT) polymers were prepared, and their spectroscopic properties were studied. These polymers were well defined, with polydispersity indices no larger than 1.20 and regioregularities that were above 90% for each member of the series. The P3HT polymers were characterized using UV–vis and fluorescence spectroscopy, and their specific refractive index increments were measured in tetrahydrofuran. The influence of the molecular weight of these polymers on their maximum absorbance and emission wavelengths, molar extinction coefficients, and refractive index increments was studied.