The β-phase of poly(9,9-dioctylfluorene) as a potential system for electrically pumped organic lasing

The beta-phase of poly(9,9-dioctyl-fluorene) (PFO) shows a very low amplified spontaneous emission threshold because of its well-resolved emission spectrum. Within the amorphous PFO, the beta-phase sites act similar to a dopant as they trap excitons and charges. The figure shows the blue-light-emitting beta-phase in a PFO solution.