Blue Emitting Polyfluorenes Containing Dendronized Carbazole and Oxadiazole Pendants: Synthesis, Optical Properties, and Electroluminescent Properties

Abstract

A series of new polyfluorenes with dendritic functional cabazole and oxazole side chains have been successfully designed, synthesized, and characterized. These copolymers show good thermal properties and solubility in organic solvents, such as THF, CH2Cl2, CHCl3, toluene, etc. The photoluminescent (PL) and electroluminescent (EL) emission color quality was improved very much due to less aggregates of main chains of polyfluorenes (PFs) with the steric hindrance of dendritic functional carbazole and oxazole units. The electroluminescent devices based on these copolymers as blue emitters and host materilas were fabricated and evaluated. Balanced carriers and high efficiencies were obtained in both nonphosphorescent and phosphorescent PLEDs. The best devices were obtained by using PFCO1 materilas with the exteral quantum efficiencies of 1.03% for ITO/PEDOT/PFCO1/TPBI/LiF/Al and 11.63% for ITO/PEDOT/PFCO1:(tpbi)2Ir(acac)/Ca/Al. The results indicated that these copolymers were promising candicates for both efficient pure blue emitters and host materials for highly efficient phosphorescent PLEDs.

Carbazole-based polymers as hosts for solution-processed organic light-emitting diodes: Simplicity, efficacy

“…As main interest, dendritic side chains can efficiently suppress the formation of aggregates/excimers by their shielding effects [182,183]. Styrenic polymers P86 and P87 were notably synthesized via a ''graft-to'' approach by using a copper-catalyzed azide/alkyne cycloaddition (CuAAC) reaction.…”

Chiral and Achiral 1,3,4‐Oxadiazolophanes: A New Class of Cyclophanes in Supramolecular Chemistry

“…Oxadiazole derivatives are used widely as electron transporting and hole blocking materials in Organic Light Emitting Devices because of their electron deficiency, high thermal and oxidative stability. They offer applications in electroluminescence , liquid crystals , molecular wires , and dendrimers .…”

Synthesis and characterization of electrophosphorescent jacketed conjugated polymers

“…Polyfluorene (PF) and its derivatives are highly efficient blue‐light materials6, 7 and good host materials 8, 9. However, the planar structures of PFs may easily form intermolecular aggregation, leading to the undesirable changes of emitting colors 10, 11.…”