Material and Interface Engineering for Highly Efficient Polymer Light Emitting Diodes

Polymer light-emitting diodes (PLEDs) have great potential to compete with LCD displays that are currently used for computer and television screens. The efficiency and stability of PLEDs still need to be improved in order to fully realize the advantages of low cost and ease of fabrication provided by organic materials. Our effort in improving the PLED's performance have been focused on two parallel approaches: 1) Modify the interface between polymer and the charge-injection electrodes for more efficient device structures; 2) Enhance the efficiency of PLEDs through the development of new conjugated materials with balanced charge-transporting properties. In this paper, we review our recent progress on the interface engineering between polymer and electrodes to optimize charge-injection, -transport, and -recombination in PLEDs, as well as on the material engineering to tune the emission color, electron affinity, and charge mobility.