Polyoctylfluorene thin films were made using novel solvent vapor assisted spin-coating method, which adds solvent into spin-coater and seal it for several minutes before spin-coating to form a solvent vapor atmosphere. The absorption, photoluminescence spectra, electroluminescence spectra and X-ray diffraction patterns demonstrate that β phase directly generate in such thin film while the thin film made by using normal method is amorphous, which means such method combines normal spin-coating and solvent vapor annealing together into one simply and fast process. The brightness and efficiency of related electroluminescence device are also enhanced due to the self-dopant effect.Graphical abstract

Highlights► Solvent vapor assisted spin-coating (SVASP) method is proposed. ► SVASP is equivalent to combination of spin-coating and solvent vapor annealing. ► β Phase PFO can directly generate using SVASP method.