Effects of single walled carbon nanotubes on the electroluminescent performance of organic light-emitting diodes

Effects of single walled carbon nanotubes (SWNTs) on the electroluminescent performance of organic light-emitting diodes (OLEDs) have been investigated by mixing them in a hole-conducting layer and in a light-emitting layer in OLEDs. We found that SWNTs play different roles when used as polymer:SWNT composites in OLEDs. When used in a hole-conducting layer, SWNTs facilitate the charge transport in the transport layer and on the other hand they also act as the exciton quenching centers at the transporting/emitting interface provided their concentration is high enough. When used in a light-emitting layer, SWNTs act as an n-type dopant to increase electron transport in p-type electroluminescent film and subsequently improve the balancing degree of bipolar injection, leading to an enhancement in the electroluminescence efficiency.

This paper report the experimental studies on the effects of single walled carbon nanotubes (SWNTs) on the electroluminescent performance of organic light-emitting diodes (OLEDs). We found that SWNTs play different roles when used as polymer:SWNT composites in OLEDs. When used in a hole-conducting layer, SWNTs facilitate the charge transport in the transport layer and on the other hand they also act as the exciton quenching centers at the transporting/emitting interface provided their concentration is high enough. When used in a light-emitting layer, SWNTs act as an n-type dopant to increase electron transport in p-type electroluminescent film and subsequently improve the balancing degree of bipolar injection, leading to an enhancement in the electroluminescence efficiency.Figure optionsDownload as PowerPoint slideHighlights
► In hole-conducting layer the SWNTS can facilitate the charge transport.
► In light-emitting layer the SWNTs can balance electron and hole injection.
► The SWNTs can have multi-functions to enhance organic EL in OLEDs.