A carbon nanotube composite as an electron transport layer for M3EH-PPV based light-emitting diodes

We have studied the effects of using a multiwalled carbon nanotube (MWNT) and poly(m-phenylene-vinylene-co-2, 9-dioctyloxy-p-phenylene-vinylene) (PmPV) composite as an electron transport layer (ETL) in poly[2, 5-dimethoxy-1,4-phenylene-vinylene-2-methoxy5-(2'-'-ethylhexyloxy)-1,4-phenylene-vinylene] (M3EH-PPV) based electroluminescent devices. Single layer (SL) devices using only M3EH-PPV, double layer (DL) devices with poly(9-vinylcarbazole) (PVK) and poly[(N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4, 4 'diamine)-diyl-co-diphenyl-xylylene] (poly-TPD-DPX) as hole transport layers (HTLs), DL devices with the PmPV-MWNT composite as an ETL, and triple layer (TL) devices with the HT and ETLs were prepared. These structures were investigated in terms of current-voltage-luminance characteristics and of electroluminescence (EL) behaviour. When using the PmPV-MWNT composite layer, a significant increase in brightness was observed.