The polymer light-emitting diode (PLED) has evolved since inception in 1990 [1] to a technology that is now competing with liquid-crystal displays. Fabrication of low-cost, large-area flat panel displays on both rigid and flexible substrates, with high brightness and good contrast at low power consumption have now become possible. This paper describes the fabrication of PLEDs, and in particular, the different processes for achieving patterned layers of conducting polymers. The processes considered here include the widely reported inkjet printing technique and plotting. The latter is demonstrated for the first time in this paper. With both techniques, the ink is replaced with an appropriate polymer solution. Although ink jet printing offers relatively small feature sizes and currently meets the resolution requirements for high information content displays, there are a variety of other application areas (e.g. electronic labeling) which can be met with the plotting technology where resolution requirements are not as critical.
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