Indium tin oxide modified transparent nanotube thin films as effective anodes for flexible organic light-emitting diodes

Sn-doped In2O3 (ITO) modified single-walled carbon nanotube (SW-CNT) transparent electrodes are fabricated on flexible polyethyleneterephthalate (PET) substrates by stamp printing SW-CNT films, followed by room temperature ion-assisted deposition of ITO. Polymer light-emitting diodes (PLEDs) using such film as anodes exhibit superior performance versus CNT-only controls. Flexible PLEDs with the following structure: PET/CNT(30 nm)-ITO(45 nm)/poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate)/[poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)diphenylamine)]+{4,4′-bis[(p-trichlorosilyl propylphenyl)-phenylamino]biphenyl}/[poly(9,9-dioctylfluorene-co-benzothiadiazole)]/CsF/Al, achieve a maximum light output of 8900cd∕m2 with a current efficiency of 4.5cd∕A. Bending test comparisons with ITO/PET show the ITO modified CNT/PET electrodes to be far more mechanically flexible.