Zinc-based transparent coating could cut cost of solar cells

Prof Peter Edwards, head of Inorganic Chemistry at Oxford University and Fellow of St Catherine’s College, Oxford, will use the £25,000 Materials Science Venture Prize, awarded by the Worshipful Company of Armourers and Brasiers, to develop manufacturing processes for his group’s transparent conducting oxide coatings.

Currently, Indium tin oxide (ITO) is used by over 97 per cent of the transparent conducting oxide market as it possesses a near-ideal combination of high visible-light transparency and high electrical conductivity. The total market for ITOs is estimated to be worth $26.8bn by 2016.

However, indium metal is relatively scarce, expensive and has a highly volatile price. China produces over half of the world’s indium and has recently reduced its export quotas.

The new coatings were developed as part of a programme to investigate low-cost, earth abundant materials and inexpensive deposition routes which could be used for large-area transparent conducting oxide coatings for products such as solar photovoltaic cells. These coatings are based on silicon-doped zinc oxide and provide an alternative to indium tin oxide.