An investigation of the emission solvatochromism of a fluorene-triarylamine copolymer studied by time resolved spectroscopy

Abstract

The hole transporting fluorene-triarylamine copolymer poly{9,9-dioctylfluorene-co-[N,N′-bis(4-methoxyphenyl)-N,N′-diphenyl-1,4-phenylenediamine]} [PFMO] has been investigated by absorption and emission spectroscopy as both spin-coated films and solutions. The peak wavelength of the steady-state photoluminescence emission and its decay time depend strongly on the dielectric constant of the solvent. The absorption spectrum is, however, largely insensitive to the choice of solvent. These observations suggest the presence of a strongly polar excited state with a charge-transfer character.