The morphologies, synthesis, and photophysical characterizations of poly[2,7-(9,9-dihexylfluorene)]-block-poly(2-(diethylamino)ethylmethacrylate) using amphiphilic rod-coil (PF-b-PDEAEMA) were demonstrated. The aggregation morphologies of PF13-b-PDEAEMA100 were manipulated by tuning the selectivity of mixed THF/methanol solvents with methanol contents ranging from 0 to 90 vol%. The morphological transformation of PF13-b-PDEAEMA100 caused significant changes in its photophysical properties, including absorption, fluorescence spectra, and fluorescence quenching. Moreover, the thermal stability of PF13-b-PDEAEMA100 was investigated by varying the annealing temperature. The results of the present study suggest that the solvent selectivity influences the photophysical properties and aggregation morphologies of rod-coil block copolymers in solid and solution states.