Key points are not available for this paper at this time.
The β-phase of poly(9,9-dioctylfluorene) (PFO) shows a very low amplified spontaneous emission threshold because of its well-resolved emission spectrum. Within the amorphous PFO, the β-phase sites act similar to a dopant as they trap excitons and charges. The figure shows the blue-light-emitting β-phase in a PFO solution.
Rothe et al. (2006) studied this question.