Photo and electroluminescence from fluorene containing copolymers

Abstract

This paper demonstrates that although excimer formation in the photoluminescence (PL) and electroluminescence (EL) spectra of poly(fluorene) homo and copolymers seems to be a troublesome problem, this can be can eliminated for high polymers by incorporating a relatively small amount of anthracene into the polymer main chain linked via the 9,10-positions. These material give a colorfast emission for both PL and EL even after annealing. Given the desirable characteristics of DHF/ANT copolymers, a variety of copolymers containing electronic rich and/or electron deficient comonomers are prepared. The former leads to red-shifts in both the EL and PL while the latter lead to blue-shifts. In each case, the emission is colorfast and improved quantum efficiencies are observed when both monomers are incorporated in the same copolymer molecule.