2015 Faraday medal

Professor Henning Sirringhaus, University of Cambridge, for transforming our knowledge of charge transport phenomena in organic semiconductors as well as our ability to exploit them.

Professor Henning Sirringhaus

Henning Sirringhaus is a highly creative, versatile and productive physicist who is not afraid to tackle challenging problems. His research crosses the interface between condensed matter physics, materials science and electrical engineering. In several areas of soft matter electronics and opto-electronics research he has carried out landmark investigations which have given birth to stunning new technologies and industries.

Sirringhaus has greatly transformed the understanding and exploitation of charge transport physics in organic semiconductors. When he started to work on polymer field-effect transistors (FETs) in the late 1990s, they had poor mobilities, 10,000 times lower than thin film silicon. In 1999, using solution self-organisation mechanisms, he pioneered improvements in the mobility to values comparable with silicon, showing that their origin depends on the ability of the polaronic charge carriers to delocalise over several polymer chains. By 2000 he developed an inkjet printing process for polymer FETs which allowed fabricating well-defined multilayer structures by solution-deposition and achieving high printing resolution through surface energy patterning. This constituted one of the first practical printing processes for organic FETs, forming the basis in 2000 for Plastic Logic, a spin-off company that has successfully commercialised flexible displays based on organic semiconductors.

Sirringhaus’s research has concentrated on fundamental physics, scoring notable breakthroughs including the discovery of efficient electron transport in a broad range of polymer semiconductors provided with trapping-free gate dielectrics, and the realisation of ambipolar field-effect transistors, where electron and hole accumulation layers are formed simultaneously with light-emission at their boundary. Low-temperature processing was also significantly extended to high performance metal oxide semiconductors. Sirringhaus’s group first reported band-like transport characteristics in a high-mobility solution-processed molecular semiconductor and then pioneered the measurement of the molecular vibrations they had identified as limiting transport. In 2013 his group first observed the inverse spin-Hall effect in a conjugated polymer and pure spin-current transmission through organic semiconductors, opening exciting opportunities for spin-based information processing in organic materials. They recently reported high-mobility conjugated polymers where transport approaches disorder-free limits, overcoming a traditional limitation of these materials.