American Chemical Society, Journal of Physical Chemistry C, 23(119), p. 13144-13152, 2015
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The current research presents using a nanocomposite comprising of a cationic conjugated polyelectrolyte (CPE), Poly[(2,5-bis(2-(N,N-diethylammonium bromide)ethoxy)-1,4-phenylene)-alt-1,4-phenylene] or (PPPNEt2.HBr), with graphene oxide (GO) as a new hole injection layer (HIL) for organic light emitting diodes. It is demonstrated that using the designed ionically functionalized water soluble conjugated polymers instead of polyethylene dioxythiophene: polystyrene sulfonate (PEDOT:PSS) is a promising approach to overcome strong acidic nature of PEDOT:PSS besides excluding its non-conductive PSS part. As the other aspiration of this work, we introduce a good partner for dissolving and spin-casting of GO as a simple and economic technique to use the hole conductive and electron blocking nature of GO in hole injection portion of assembled devices. Using this new binary blend showed enhanced charge carrier mobility, good electroluminescent and J-V characteristics in comparison with the conventional devices. Such improvement is interpreted with induced ion space charge of HIL at the interface and resulting electric field screening effect due to ion migration.