Synthesis and Characterization of a Bipolar Light-Emitting Copolymer Consisting of Tetraphenyldiaminobiphenyl and Bis-Quinoline Units

A new luminescent copolymer containing both an efficient hole-transporting moiety, tetraphenyldiaminobiphenyl, and an electron-affinitive light-emitting moiety, bis-quinoline, was prepared. It possesses high thermal stability (decomposes at temperatures above 461 °C), excellent electrochemical reversibility, good thin-film-forming ability, and bright light-emitting property. Electrical characterization of a two-layer diode device based on the structure of ITO/CuPc/TPD−PQ/Al showed excellent electroluminescence performance (bright yellow emission, a rectification ratio greater than 105, and a low turn-on voltage of 3.8 V).