Highly efficient green PLED based on triphenlyaminesilole-carbazole-fluorene copolymers with TPBI as the hole blocking layer

• 3,4-Triphenylamine-silole was incorporated into the fluorene-carbazole backbone.
• Highly efficient green-emitting materials were designed and synthesized.
• Green PLEDs with high efficiency and brightness were obtained.

Triphenylamine-containing silole was copolymerized with fluorene and carbazole by Suzuki coupling reactions to obtain a series of copolymers. The chemical structures, electrochemical properties, and optoelectronic properties including absorption, photoluminescence, and electroluminescence of these copolymers were well characterized. The highest absolute photoluminescence quantum efficiency of these polymers in films was up to 81%. 1,3,5-Tri(N-phenylbenzimidizol-2-yl)benzene hole blocking layer greatly boosts the external quantum efficiency up to 4.3% from 0.06%. The external quantum efficiency was further raised to 5.4% by blending copolymer with 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD), and the largest luminous efficiency as high as 13.6 cd/A was realized at the same time.