Zinc could replace 'rare earths' in solar cells, screens

Costly and rare indium , used in solar cells, and screens for TVs, computers, and mobile phones, could be replaced with abundant and cheap zinc, scientists at Oxford University believe.

Because of its combination of high transparency and high electrical conductivity indium tin oxide ( ITO ) dominates the global market for coatings for solar cells and LCD displays. The market for the material is estimated to be worth $26.8bn by 2016.

However indium, a so-called ' rare earth ' metal, is relatively scarce and expensive and its supply is tightly controlled - China produces over half of the world’s indium and recently reduced its export quotas.

Peter Edwards and colleagues at Oxford University's Department of Chemistry have been investigating how to make alternative coatings from cheaper, more abundant materials. Their research has come up with new coatings based on silicon-doped zinc oxide.

The Oxford team has been working closely with Isis Innovation , the University's technology transfer company, to protect and commercialise its research. As Isis report today, the team has just won the Materials Science Venture Prize, awarded by the Worshipful Company of Armourers and Brasiers, to develop manufacturing processes for the group's coatings.