White light emitting devices by doping polyfluorene with two red emitters

The photo and electroluminescent properties of a single-layer multi-component blend composed of only blue and red emitters were studied. The blue emitter poly(9,9-dihexyl-2,7-fluorene)] (LaPPS10) was used as the matrix, and the two red emitters, poly[2-methoxy-5-(2-ethylhexoxy)-1,4-phenylene vinylene] (MEH-PPV) and 4-(dicyanomethylene)-2-methyl-6-(dimethylaminostyryl)-4H-pyrane (DCM), as the dopants. A detailed study of this system was performed in solution and in the solid state, comparing the photophysics aspects of emission spectra of the blend and those of the matrix with each one of the components. The white OLED device exhibited CIE chromaticity coordinates x = 0.30 and y = 0.31. Electro and photoluminescence emission profiles were discussed.

Figure optionsDownload as PowerPoint slideHighlights
► White light EL emission was obtained from single layer with two red emitters.
► Blue emitting was the matrix.
► Exciton formation occurs preferentially in the lower bandgap components.
► Control of the concentration of dopants possible to obtain white light emission.
► White OLED device exhibited CIE chromaticity coordinates x = 0.30 and y = 0.31.