The electron-injection capability of solution-processed cesium stearate films in organic light-emitting diodes is investigated. Cesium stearate, which is expected to exhibit good solubility and film formation due to its long hydrocarbon chain, is synthesized using a straightforward procedure. Light-emitting diodes are fabricated using orange-, yellow-, and blue-emitting conjugated polymers, comprising a cesium stearate electron-injection layer deposited from ethanol solution. It is demonstrated that these devices perform as well as benchmark devices using vacuum-deposited barium as electron-injection layer, without loss of color purity.
Received 05 December 2012Accepted 21 January 2013Published online 04 February 2013
This work was supported by the Dutch Polymer Institute (DPI), Project No. 678. The authors would like to acknowledge the technical assistance of Jan Harkema. We also thank E. H. Valkenier-Van Dijk and A. J. Kronemeijer for assistance in the synthesis of cesium stearate.
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