PL Quenching of Poly(3-hexylthiophene) by 2,2′,7,7′-Tetradiphenylamino-9,9′-Bifluorenylidene

Abstract

2,2′,7,7′-Tetradiphenylamino-9,9′-bifluorenylidene, TDPABF, was synthesized by reductive dimerization using Lawesson's reagent. It is soluble in common organic solvents such as dichloromethane, chloroform, and 1,2-dichlorobenzene. Its synthesis was confirmed by ¹H-, ¹³C- NMR, MALDI-TOF, and FT-IR spectroscopy. Its HOMO and LUMO energy levels were –5.33 eV and –2.98 eV, respectively, using photoelectron spectroscopy and UV-Vis absorption spectra. Its fluorescence quenching properties were investigated through a Stern-Volmer quenching experiment. The PL intensity significantly decreased on increasing the concentration of TDPABF in a P3HT chloroform solution. The calculated Stern-Volmer quenching constant was 9.1 × 10⁴ M⁻¹, which is higher than that reported for PC₆₁BM.

Keywords:

• 9,9′-bifluorenylidene derivative
• electron acceptor
• photoluminescence quenching