Photoluminescence and electroluminescence properties of a new PPV derivative containing oxadiazole segments

The synthesis of a new PPV derivative (poly [(2,5-diphenylene-1,3,4-oxadiaz ole)-4,4'vinylene] (O-PPV) oligomer) and the investigation of the absorptio n and photoluminescence (PL) properties of O-PPV in the forms of solution a nd solid-state film are reported. Our results showed that the PL in the cas e of solid-state originates from an excimer or interchain charge transfer c omplex. To understand the nature of carrier transport, two types of devices : ITO/PPV/O-PPV/Al and ITO/O-PPV/Tb(AcAc)(3)Phen/Al were fabricated. Their electroluminescence result indicates that O-PPV has both hole and electron transport abilities. As a result, the EL efficiency of the single layer O-P PV device is higher compared with that of the single layer PPV due to the b alance of charge injection and transport. The electron transport proper-ty is attributed to the property of excimers. (C) 2000 Elsevier Science S.A. A ll rights reserved.