We presented comprehensive photoluminescence (PL) and electroluminescence (EL) studies of polyfluorene based electroactive polymer (SF4) containing double bond side chain to investigate its characteristics as a function of temperature. Annealing treatment was conducted for thin films on glass substrates and also for the organic light emitting diodes (OLEDs) at different temperatures. While polymer thin film coated on to glass substrate annealed at < 150 degrees C exhibited green color emission, OLEDs that annealed at > 150 degrees C shifted white color emission. It was implying that the emission was taking place interchain interaction. Phase modulation at higher annealing temperatures was occurred on the thin film as shown AFM images. Further, annealed polymer film with 120 degrees C exhibited the best performance in OLED device with luminance 5241 cd m (-2), a maximum efficiency 1.54 cd A (-1) and external quantum efficiency 0.54% compared to other polymer films annealed with different temperatures. (C) 2017 Elsevier B. V. All rights reserved.