Enhanced Contact Layer Organic Light Emitting Diodes

Organic based light emitting diodes have made significant advances in the past few years. An important factor in device performance is the transparent conducting contact layer. Presently, indium tin oxide (ITO) is used because it is an accepted standard and has a great deal of invested development. However, for several reasons, including work function, physical stability, and band alignment to organics, ITO is not necessarily the ideal contact layer for a given organic LED. In Phase L we propose to produce a series of alternative transparent and conductive films, fabricate working organic devices and evaluate performance issues. The new transparent and conductive oxide films will be produced using our existing MOCVD equipment and established processing techniques. The organic LEDs will be fabricated by thermal evaporation of tris 8--hydroxyquinoline aluminum (Alq) and naphthyl-substituted benzidine (NPB) at The University of Rochester, with guidance by researchers at Eastman Kodak. Films and devices will be evaluated by all participants. In Phase II we will refine the contact layer film properties and optimize working OLEDs, transitioning our device improvements into manufactured products for Phase III.