K Trivedi et al 2009 Nanotechnology 20 405204 doi:10.1088/0957-4484/20/40/405204
K Trivedi1, U S Bhansali2, B Gnade2 and W Hu1
Show affiliationsThis study reports fabrication and characterization of nanoscale organic light emitting diodes with reduced charge spreading. Nanoimprint lithography is used to make SU-8 nanochannels with ~90° sidewalls into which N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine (NPB) and tris-(8-hydroxyquinoline) aluminum (Alq3) are thermally evaporated, to avoid charge spreading. Micron grating devices are fabricated for comparison. Device characteristics show that performance is retained while scaling down to nanochannels, as no geometry dependent trend is observed. Surface potential microscopy (SPM) measurements reveal an identical periodic difference in surface potential for nanochannel and microscale grating devices. The SPM results, together with cross-sectional scanning electron microscopy observation of the physical separation of nanoscale organic light emitting diodes (OLEDs), indicate electrical separation and isolated light emission from nanoscale confined OLEDs with minimized charge spreading.
85.35.-p Nanoelectronic devices
85.60.Jb Light-emitting devices
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
Surfaces, interfaces and thin films
Issue 40 (7 October 2009)
Received 11 April 2009, in final form 21 July 2009
Published 8 September 2009
K Trivedi et al 2009 Nanotechnology 20 405204
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