White light emission was obtained from a light-emitting diodes (LEDs) prepared from an immiscible polymer bland consisting of Poly(9,9'-di hexylfluorene-2,7-divinylene-m-phenylenevinylene-stat-p-phenylenevinylene) (CPDHFPV) and poly(2-methoxy-5-(2'-ethy-hexyloxy)-1,4-phenylenevinylene) (MEH-PPV). An inefficient energy transfer between CPDHFPV and MEH-PPV was observed because the blends are partially miscible. The phase separated structure was good advantage to obtain while emitting device. The incomplete energy transfer in the blend generated a pure, while color and the emission color of this system showed a ton) sensitivity to the driving voltage.