Low-band gap and fluorescent poly(triphenylamine-thiazolo[5,4-d]thiazole) copolymer dye

Abstract

This study describes the synthesis, spectroscopy and band gap energy of a new poly(triphenylamine-thiazolo[5,4-d]thiazole) (p-TPTT) dye. The p-TPTT polymer was examined by GPC, ¹H-NMR, FT-IR, UV-vis., fluorescence, thermal analysis (TA) and cyclic voltammetry (CV). It was found that the p-TPTT has a weigh average molecular weight (M_w) of 3596 and it has good solubility in many organic solvents. The TA results showed that the p-TPTT is a stable polymer up to 400–500 °C. The E^Opt_g of the polymer was found to be 1.85 eV in DMSO and 1.55 eV in the solid phase. From the CV measurements, the HOMO and LUMO of the p-TPTT were obtained as −5.32 and −3.96 eV, respectively and the E^CV_g was measured as 1.36 eV. The p-TPTT exhibited fluorescence emissions at 500 and 522 nm. These results showed that the p-TPTT is a fluorescent and low band gap energy dye material for possible applications in LEDs and solar cells.