Carrier Transport Characteristics of the Soluble PPV Polymer with Main Chain Containing Electron-Transporting Group

A kind of novel PPV derivative containing electron transporting group on the main chain(O PPV), was synthesized according to the WITTIG HORNER mechanism. This oligo polymer( M w= 1 000 , 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 PPV mainchain. Two types of double layer devices were fabricated to study the carrier transport characteristic of OPPV. Our result showed O PPV has function both as electron transport layer and hole transport layer in double layer device, in other words OPPV has obvious bipolar transport characteristic.