Abstract: Akind of novel PPVderivative containing electron transporting group on the main chain(O-PPV), was synthesized according to the WITTIG-HORNER mechanism. This oligo polymer( M_w=1000, T_g=470 K) is soluble in chloroform and tetrahydrofuran. Single layer device ITO/O-PPV( 70 nm )/Al was fabricated, the electroluminescent(EL) spectra are essentially identical to photoluminescene(PL) spectrum. Compared with the quantum efficiency of the analogous single-layer device constructed with PPV(ITO/PPV/Al), the device ITO/O-PPV/Al is about five to eight times higher, which can be associated with the balanced carrier injection and transport owing to the attachment oxadiazole segment onto PPVmainchain. Two types of double layer devices were fabricated to study the carrier transport characteristic of OPPV. Our result showed O-PPVhas function both as electron transport layer and hole transport layer in double layer device, in other words OPPVhas obvious bipolar transport characteristic.

Key words: Organic light emitting diode, Poly( p-phenylenevinylene), Electron transport layer, Hole transport layer, Bipolar carrier transport characteristic