Multi-layer polymer light-emitting diodes with 2,3-dialkoxy-p-phenylene vinylene and its blends

A green-fluorescent polymer, poly(2,3-dibutoxy-1,4-phenylene vinylene) (DB-PPV), was synthesized and used in electroluminescent (EL) devices. By introducing a small molecular electron-transport layer in a device, the EL efficiencies were improved up to 1.26 cd/A. A polymer-blend with DB-PPV and poly(9,9-dioctylfluorene) (PF8) was also examined. The EL peak wavelength was blue-shifted to 503 nm and the EL efficiencies were improved in the polymer-blend device. A layered structure and a polymer-blend system both have shown contribution to the improvements of the polymer light-emitting diodes using DB-PPV.