Electrical and optical studies of organic light emitting devices using SWCNTs-polymer nanocomposites

The novel organic light emitting diodes with the structure of [ITO-coated glass/PEDOT:PSS/SWCNTs-PVK (polyvinylcarbazole) nanocomposites/(4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM)-doped) Alq(3)/Li:Al] were fabricated and characterized. Single-walled carbon nanotubes (SWCNTs) were synthesized by the laser ablation method and dispersed with the hole conducting polymer PVK in toluene. SWCNTs-PVK nano-composite was spin-coated on the PEDOT:PSS/ITO-coated glass and then DCM-doped Alq(3) was deposited by the cluster beam deposition methods. Studies of photoluminescence, electroluminescence (EL) and device characteristics demonstrate that whereas the EL of the devices with SWCNTs shows the same characteristic emission compared to those without SWCNTs, the device qualities such as external quantum efficiency were improved by a factor of 2-3 for SWCNTs concentrations up to 0.2 wt%. (C) 2002 Elsevier Science B.V. All rights reserved.