Abstract
In this work, we have synthesized and applied non-oxidized graphene nanoplatelets (GNPs) with high work function of 5.61 eV into the aluminum tris(8-hydroxyquinoline) (Alq3)-based organic light-emitting diodes (OLEDs) as an efficient hole transport layer (HTL). By the assistance of Py + ions from the pyridinium tribromide salt (Py+Br3-), the exfoliation of GNPs can be easily obtained via sonication. After proper filtering, the concentration of GNPs dispersed in water-ethanol mixture is about 0.2 mg/mL. To be the HTL, we presumed that a nearly full coverage of GNPs on ITO substrates can be achieved by multiple spin-coat process. Thereby, low turn-on voltage of 4.1 V (@100 mA/cm2) and high luminance of 36,000 cd/m2 (at 8.4 V) were obtained, which corresponded a luminous efficiency (2.33 cd/A) about 200 times and 1.4 times higher than that in OLEDs without any HTL and with a N,N-bis-(1-naphyl)-N,N-diphenyl-1,1′-biphenyl- 4,4″-diamine (NPB) HTL, respectively.
Original language | English |
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Pages (from-to) | 792-797 |
Number of pages | 6 |
Journal | Organic Electronics |
Volume | 15 |
Issue number | 3 |
DOIs | |
State | Published - 1 Jan 2014 |
Keywords
- Graphene nanoplatelets
- Hole injection
- Non-oxidized graphene
- Organic light-emitting diodes