In comparison with poly(9,9-dialkylfluorene)s widely used in organic optoelectronic devices, poly(9,9-dialkylfluoreneethynylene)s (PFEs) have attracted less attention partly because of their poor fluorescence quantum yield (FOY) in the solid state. In order to improve the FOY, a 1,4-bis(perfluorohexyl)benzene (BFB) unit was introduced to PFEs, and the results showed that the absolute FOY in the solid state was dependent on the mol-% of the BFB unit in the copolymers. When mol-% was 40 and 50%, respectively, the absolute FOY had greatly increased from 4.9% of PFE to 7.8 and 17.4% of the copolymers, respectively. For comparison, a 1,4-dihexylbenzene (DHB) unit was also introduced to PFE, whereas the obtained copolymer showed the absolute FOY of 3.8%, suggesting that the DHB unit was not suitable for improvement of the FOY of PFEs. Electrochemically, the PFE containing BFB units showed lower reduction potential than that of PFE. All the fluorine-containing polymers have good thermal stability.