A series of anthracene-based conjugated copolymers containing 9,10-bis(6-bromonaphthalen- 2-yl)-2-tert-butylanthracene (BNA) and 2,7-diphenyl substituted fluorene (DPPF) moieties are prepared via a palladium-catalyzed Suzuki polymerization. All of the synthesized polymers emit blue light at around 450nm and show good thermal and color stability. Their electroluminescence spectra remain unchanged at high driving voltage. The double-layer polymer light-emitting diode (PLED) fabricated with ITO/PEDOT:PSS/DPPFBNA3/CsF/Al, produces a maximum brightness of 1 650 cd · m-2 and has a luminance efficiency of 0.39 cd ·A-1. The ITO/PEDOT:PSS/ TFB/DPPFBNA3/CsF/Al multilayer PLED, incorporating a TFB layer to facilitate hole transportation, produces a maximum brightness of 5 371 cd · m -2 and a luminance efficiency of 1.18 cd · A-1.
- blue polymer light-emitting diodes
- buffer layer
- conjugated polymers