Excited-state quenching of a highly luminescent conjugated polymer

The optical properties of a luminescent polymer, poly[1,4-phenylene-1,2-di( phenoxyphenyl) vinylene], have been investigated. Its photoluminescence yie ld increases unusually in the solid-state over solution, 52%-6% respectivel y. Investigations into the stimulated emission properties of this material were carried out but no amplified spontaneous emission was observed. To inv estigate the presence of excited-state absorption features, the photoinduce d absorption spectrum was measured. An observed polaron absorption band, fr om 1.5 to 2.25 eV, overlaps the emission spectra and therefore quenches sti mulated emission. This highlights the need to consider the effects of excit ed-state absorption on the emission when synthesizing new materials. (C) 20 01 American Institute of Physics.