Semi-transparent polymer light emitting diodes with multiwall carbon nanotubes as cathodes

Semi-transparent polymer light emitting diodes (PLEDs) with double side emission using multiwall carbon nanotubes (MWCNT) sheets as top transparent cathode are described. The combination of an effective electron injection layer (EIL) and a hole blocking layer (HBL): PFN/Cs2CO3, allowed an enhancement of the electron injection from the MWCNT sheets. Those semitransparent devices exhibited a brightness and an efficiency of 220 Cd/m2 and 0.54 Cd/A, respectively, which were measured on the glass side. Our results indicate that the new architecture of laminated top-MWCNT could be useful for the development of transparent displays using a vacuum free simple dry fabrication process.