Luminescent properties of coumarin-doped MEH-PPV and novel coumarin-terminated MEH-PPV

A series of novel coumarin-terminated poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene (CT-MEH-PPV) were synthesized successfully via Gilch methodology. Luminescent properties of CT-MEH-PPV were compared with those of blend systems. A light-emitting diode based on a double-layer structure (ITO/PEDOT/CT-MEH-PPV2/Ba/Al) has shown yellow emission with a maximum brightness of 956 cd m−2 at 8.8 V and an external quantum efficiency of 0.28% at 49.5 mA cm−2. These results suggest that modification of structures of conjugated polymers with end-cappers is a convenient way to tune the emission color and to improve photoluminescent and electroluminescent efficiencies.