Light emmiting device comprising conjugated terpolymer/teroligomer capable of white light emittion

A white light emitting device comprising:

• (i) a radiation transmissive first electrode;
• (ii) a second electrode;
• (iii) a light emitting layer disposed between the first electrode and the second electrode, the light emitting layer comprising a conjugated polymer or oligomer capable of white light emission and comprising repeating units A, B and C:
• wherein represents points of attachment in the polymer chain or oligomer chain, X is selected from the group consisting of S, O, Se and NR5 and R1, R2, R5, R6, R7, R8 and R9 are independently selected from the group consisting of hydrogen, C1-20 alkyl, C2-20 alkenyl, C8-12 alkyl and C8-12 alkenyl and R3 and R4 are independently selected from the group consisting of pyridyl, pyranyl, pyridinyl, bipyridinyl, phenylpyridinyl, thienyl, furanyl, selenophenyl, fluorenyl, carbazolyl, pyrrolyl, quinolinyl, isoquionolinyl, purinyl, oxazolyl and isoxazolyl and oligomers thereof, wherein the alkyl and alkenyl of R1, R2, R5, R6, R7, R8 and R9 and aryl and heteroaryl of R3 and R4 are optionally independently substituted one or more times with a substituent selected from the group consisting of -alkyl, -alkenyl, -aryl, -heteroaryl, -alkyl-aryl, -alkyl-heteroaryl, -alkenyl-aryl and -alkenyl-heteroaryl;
• and
• (iv) a dielectric layer disposed between the light emitting layer and the first electrode and/or the second electrode.