Highly efficient white polymer light emitting diodes (WPLEDs) are demonstrated using neutral conjugated polymer surfactant PFN-OH as the electron-injection layer through solution processing. The electroluminescence spectra and luminance efficiency are strongly dependent on the morphology of the PFN-OH films. The dramatic improvement of device performance is attributed to the efficient hole-blocking ability due to mixed solvent-induced PFN-OH chain aggregation.