Since the 1980s, Cambridge researchers have pioneered the field of polymer semiconductors. Their discoveries have opened up a new scientific field and spun out into three new companies.

Low cost organic solar cells could help to revolutionise solar power production by opening up new markets

Dr Robert Trezona, Carbon Trust

Solar cells made with organic semiconductors work very differently to those made with silicon, and are closer in operating principle to photosynthesis in green plants

Professor Sir Richard Friend, Cavendish Laboratory

Lighting the way

Professor Sir Richard Friend began to work on organic semiconductors at Cambridge’s Cavendish Laboratory in the mid 1980s, curious about whether polymers made from conjugated molecules would behave as semiconductors in the same way as silicon.

While studying these compounds in Friend’s laboratory, Dr Jeremy Burroughes noticed that when a voltage was applied, a green light was emitted from the electrode. Together with Professor Donal Bradley, they realised these polymer light-emitting diodes could have many applications. With colleagues in the Department of Chemistry, Professors Andrew Holmes and Paul Burn, they filed patents for the discovery in 1989 and 1990. Later that year they revealed their discovery in Nature, and development of this work was taken forward through the formation of Cambridge Display Technology.

As the research progressed, Friend and his colleagues Professor Henning Sirringhaus and Professor Neil Greenham spun out other businesses, including Plastic Logic and Eight19, to exploit emerging applications of the technology. And, as a result of the group’s research, the University and TTP won a competition to set up an Advanced Photovoltaics Research Accelerator at Cambridge with £5m funding from the Carbon Trust.

Cambridge Display Technologies

As the originator of polymer organic light emitting diode (P-OLED) technology, Cambridge Display Technology (CDT) – set up in 1992 – has continued to lead the field in its development.

After securing its first licenses in 1996 from Philips, in 1999 it received investment of $133m from private equity funds. CDT was floated on the NASDAQ in 2004, and in 2007 was acquired by Japanese chemical company Sumitomo Chemical Company for $284m. Sumitomo Chemical has invested in CDT, which has a world-class portfolio of intellectual property.

At its state-of-the-art R&D centre near Cambridge, CDT – which employs 140 staff – is continuing research into display and lighting applications, as well as organic semiconductor and photovoltaic applications.

Already found in digital cameras and smartphones, organic LEDs are now entering the large-screen TV market, with more mass market products expected in the next few years.

P-OLEDs have great potential for creating large area, diffuse light sources. With the global market for OLED lighting set to take off, CDT and Sumitomo are developing materials and manufacturing capability for low cost, large area OLED lighting.

Plastic Logic

Plastic Logic was founded in 2000 by Friend and Sirringhaus. Since then, the company has gone on to become a leading developer in plastic electronics manufacturing. Its revolutionary plastic resistor technology enables electronics to be manufactured on flexible or plastic sheets.

Plastic Logic developed the first industrial-scale process for printing electronic circuits on plastic substrates, a process capable of making incredibly thin, light and robust displays – from flexible e-readers to signage.

In 2015, the technology arm of Plastic Logic was spun out to form a new company, FlexEnable and its manufacturing arm renamed Plastic Logic Germany.

Eight19

Named after the number of minutes and seconds it takes sunlight to reach the Earth, Eight19 was set up in 2010 by Friend, Greenham and Sirringhaus to develop and make solar cells based on printed plastic. Today, its state-of-the-art printing and testing facilities are based at Cambridge Science Park.

Flexible, robust and lightweight, these solar modules can be manufactured more quickly and cheaply than conventional solar cells. And with a fraction of the embedded energy of conventional solar units, printed plastic solar modules are ideal for consumer and off-grid applications.

As well as new solar technology, Eight19 pioneered Indigo, an innovative new payment model based on mobile phones. With millions of off-grid consumers in sub-Saharan Africa, tapping into the mobile phone network is helping bring solar power to the poorest communities in the remotest parts of the region.

In 2012, Indigo was spun off into Azuri Technologies, which is giving rural homes and small businesses across Kenya, Malawi, Zambia, South Sudan, Uganda, Rwanda and South Africa a affordable access to electricity – thanks to the payment model developed in Cambridge.