Synthesis and characterization of a high-efficiency light-emitting alternating copolymer

A new high-efficiency light-emitting alternating copolymer of triphenylamin e and pure PPV (TPA-PPV) has been designed and synthesized. The copolymer w as highly soluble in common solvents. It could be spin cast onto various su bstrates to give highly transparent homogeneous thin films without heat tre atment. The fluorescence quantum yield in benzene is almost up to 1.00. The maximum fluorescence wavelength for this alternating copolymer appeared ar ound 470 nm. The fluorescence of TPA-PPV solution quenched by C-60 was exam ined, and the result indicated that a strong interaction exists between TPA -PPV and C-60 at the exited state. A primary single-layer LED based on ITO/ TPA-PPV/AI has been fabricated, and the onset voltage is only 1.5 V and a b right green light was observed. The electroluminescence spectrum gives a pe ak at 510 nm when the operating voltage of 17 V was applied. The photolumin escence spectrum also appeared at the same wavelength as the electrolumines cence, indicating that the same excited states are involved in the two proc esses. (C) 1999 John Wiley & Sons, Inc.