High Efficient White-Phosphorescence PLEDs by Using Water/Alcohol-Soluble Polyelectrolyte as an Electron Injection Layer

Abstract:

High efficient white polymer light-emitting diodes (WPLEDs) were fabricated with blue- fluorescent polymers(PFO) and yellow- phosphorescent polymers(PFCz₂-NPYIrm₅) blending as light emitting layer, and a water/alcohol-soluble polymer poly [(9,9-bis(3′-((N,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene) - 4,7-(2,1,3- benzoselenadiazole)]dibromide(PFN) as electron injection layer. The structure of the devices used here is: ITO/PEDOT-PSS(40nm)/PVK(30nm)/PFO: PFCz₂-NPYIrm₅ (60nm)/PFN(20nm)/Ba(4nm)/Al(120nm). When the doping concentration of PFCz₂-NPYIrm5 was 1% and PFN film thickness was about 20nm, the EL emissions from the host and the guests were observed simultaneously and the efficient white light emission with coordinates of (0.34,0.32) was achieved. A maximum external quantum efficiency of 4.8% and luminous efficiency of 6.6cd/A was obtained at 8.5V.

• Periodical: Applied Mechanics and Materials (Volumes 84-85)
• Pages: 494-498
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.84-85.494
• Online since: August 2011
• Authors: Nan Liu Liu, Hong Yu Zhen, Wei Xu
• Keywords: Polymer Light Emitting Diode, Solution Process, White Light

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