Use of a new blue emitter in color-stable, flexible, polymeric white light-emitting diodes with a simple structure

چکیده مقاله

New, polymeric white light-emitting diodes with the structure ITO/PEDOT: PSS/BFE + MEH-PPV/Al have been fabricated, in which poly(9,9-dioctylfluorene- co-N,N¢-di(phenyl)-N,N¢-di(3-carboethoxyphenyl) benzidine (BFE) was used as the blue emitter host and poly [2-methoxy-5-(2¢-ethyl-hexyloxy)-1,4- phenylene vinylene (MEH-PPV) as the red emitter guest. A poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) layer was spincoated as the hole-injection layer (HIL) on a flexible poly(ethylene terephthalate)/ indium tin oxide (PET/ITO) substrate; the cathode was aluminium (Al). The entire simple, low-cost fabrication process was performed without any need for a glove box. The effect of PEDOT:PSS films prepared from the PEDOT:PSS/water solution with two different volume ratios (1:3 and 1:6) as the HIL on the lifetime and output performance of devices was investigated. The device fabricated by using the volume ratio 1:3 emitted white light with high color quality and Commission Internationale de l’Eclairage (CIE) coordinates of (0.34, 0.38), and had a long operating lifetime.