Polymer electroluminescence: principles and prospects

Organic electroluminescence has been the subject of considerable interest in the last few years following reports from the Eastman Kodak and Kyushu University groups, and subsequently many others, on sublimed films of low molecular weight dyes. We have shown that another class of organic, namely the conjugated polymers, can be used as the emissive layer in electroluminescent diodes and that these films have good stability. Combined with their ease of deposition over large areas, this makes them an attractive new category of electroluminescent material. Following our first report in 1990 on poly(p-phenylene vinylene) light emitting diodes, considerable progress has been made in enhancing device characteristics and in chemically tuning the colour of emission. In this paper I will review the status of progress in conjugated polymer electroluminescence and describe some results. I will also provide a personal view of the prospects that this new area offers for lighting and display applications and highlight some of the current difficulties