Since the first successful fabrication of polymer light-emitting diodes(PLEDs)

much effort has been devoted to the synthesis of new electroluminescent materials and the characterization of their photo-physical properties for their enormous potential application.Generally

conjugated polymers

such as MEH-PPV

dissolved in different solutions show various aggregation and morphology due to the solvent-polymer interactions.This is becacuse such difference is partly retained in polymer films

which are spin-coated from solutions.As a result

delocated and located electronic states of conjugated polymer

which determine the opto-electronic properties of polyme are affected strongly by the morphology and aggregation of polymer chains.Usually

close packing the conjugated polymer chains makes the distance of chains smaller and enhances the excimer formation

which reduces the PL quantum efficiency and makes PL spectrum a red-shift.However

little information has been attained about the influence of conformation structure of non-conjugated polymer on luminescent properties.But non-conjugated polymers are very important for the fabrication of PLEDs.It is very important to understand the nature of non-conjugated polymer chrompohores and their electronic and photonic properties.Here

a new type of poly(tris-8-hydroxyquinoline)derivative(Palq)spin casted from different solvents is reported to show obvious influence of film morphology on the absorption and luminescence spectra.When Palq film is spin coated from ethanol solution

their absorption and luminescent spectra show significantly red-shift in comparison with that of Palq film spin casted from chloroform solution.The PL peak of Palq film from ethanol solution locates at 510nm and its EL peak is at 540nm.While PL peak of Palq film from chloroform solution is at 488nm and its EL peak at 460nm.This is because that ethanol and chloroform show different polarity

the aggregation of Palq is different.While these different solutions are spin-coated into films

the aggregation of Palq solutions can be partly retained

which results in the difference of electronic structure of Palq films.As a result

the Palq films from different polar solvent represent different luminescent properties.Therefore

the choice of solvent is very important for luminescent characteristics of non-conjugated polymers in the fabrication of polymer light-emitting diodes.