A polymer blend system F8(1-x):SYx based on poly(9,9-dioctylfluorene) (F8) from the family of polyfluorenes (PFO) and a poly(para-phenylenevinylene) (PPV) derivative superyellow (SY) shows highly efficient energy transfer from F8 host to SY guest molecules. This has been realized due to a strong overlap between F8 photoemission and SY photoabsorption spectra and negligibly low self-absorption. The steady-state and time-correlated spectroscopic measurements show an increased photo-luminescence quantum efficiency (PLQE) and lifetime (tau) of SY, with an opposite trend of decreasing PLQE and tau of F8 excitons with increasing SY concentration, suggesting the Forster resonance energy transfer (FRET) to be the main decay pathway in the proposed system. The systematic study of the exciton dynamics shows a complete energy transfer at 10% of SY in the F8 host matrix and a Forster radius of similar to 6.3 nm. The polymer blend system exhibits low laser and amplified spontaneous emission thresholds. An ultrahigh efficiency (27 cd.A(-1)) in F8(1-x):SYx based light emitting diodes (LED) has been realized due to the intrinsic property of a well-balanced charge transport within the emissive layer. The dual pathway, that is, the efficient energy transfer between the blended molecules via resonance energy transfer, and the charge-traps-assisted balanced transport makes the system promising for achieving highly efficient devices and a potential candidate for lasing applications.