Organic Electronics - History

History

In 1862, Henry Letheby obtained a partly conductive material by anodic oxidation of aniline in sulfuric acid. The material was probably polyaniline. In the 1950s, it was discovered that polycyclic aromatic compounds formed semi-conducting charge-transfer complex salts with halogens. This finding indicated that organic compounds could carry current.

High conductivity of 1 S/cm in linear backbone polymers (in an iodine-"doped" and oxidized polypyrrole black) was reported in 1963. Likewise, an actual organic-polymer electronic device was reported in the journal Science in 1974. This device is now in the "Smithsonian Chips" collection of the American Museum of History (see figure).

Conducting polymer research flourished after the 1977 discovery that polyacetylene can be oxidised ("doped") with halogens to any degree from insulating or semiconducting to highly conducting. For this work, Alan J. Heeger, Alan G. MacDiarmid, and Hideki Shirakawa were jointly awarded the Nobel Prize in Chemistry in 2000.

Ching W. Tang who built the first organic light-emitting diode (OLED) and organic photovoltaic cell is widely considered the father of organic electronics

Conduction mechanisms in such materials involve resonance stabilization and delocalization of pi electrons along entire polymer backbones, as well as mobility gaps, tunneling, and phonon-assisted hopping.

Technology for plastic electronics on thin and flexible plastic substrates was developed at Cambridge University’s Cavendish Laboratory in the 1990s. In 2000, Plastic Logic was spun out of Cavendish Laboratory to develop a broad range of products using the plastic electronics technology.