Synthesis and characterization of new poly(p-phenylenevinylene) derivative containing 5,5 '-diphenyl-2,2 '-p-(2,5-bis-hexyloxyphenylene)bis-1,3,4-oxadiazole and distyrylbenzene moieties

摘要

A PPV-based conjugated copolymer DIOXA-PPV containing electron-affinitive bis- 1,3,4-oxadiazole and hole-transporting distyrylbenzene derivative was synthesized via Homer-Wadsworth-Emmons reaction. The HOMO, LUMO energy levels and band gap of DIOXA-PPV are determined to be -5.06, -2.98 and 2.08 eV, respectively. The photoluminescence (PL) maxima show gradually transition from 515 to 544 nm as the concentrations of DIOXA-PPV in C2H2Cl4 increase from 10(-7) to 10(-3) M due to the formation of excimer. Single-layer light-emitting diode (LED) with a structure of ITO/DIOXA-PPV/Al emits bright yellow emission, the threshold voltage and maximum luminance are 4.6 V and 188 cd/m(2), respectively. The EL emission maximum locates at 541 nm, which is corresponding to the excimer emission. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 26]