Abundant zinc could replace scarce and pricey indium in solar panels

Oxford University researchers looking for more efficient and cheaper ways to manufacture solar panels have found a possible solution in lowly base metal zinc.

For as long as photovoltaic panels have been in large-scale commercial production indium – a relatively scarce and expensive rare earth element – in the form of indium tin oxide (ITO) has been the key ingredient.

Solar Power Portal quotes Professor Peter Edwards, Head of Inorganic Chemistry at the University of Oxford and lead scientist on the research project, that won the Materials Science Venture Prize by the Worshipful Company of Armourers and Brasiers this week:

“Zinc is a much more abundant material than indium, and our silicon-doped zinc oxide material offers electrical conductivities around two thirds of ITO, with comparable optical transparency. In addition to solar cells, our new coating could be used with lighting displays and LCD displays used in smart phones, computers and televisions.”

Even though the zinc based transparent material is a less efficient conductor, it has great advantage in manufacturing.

ITO has to be applied to its substrate material in a vacuum chamber. The silicon doped zinc oxide is a liquid that can be sprayed on like paint, making it practical to apply to large and malleable surfaces potentially including aircraft wings and fuselages or motor vehicles.

Indium is produced as a byproduct primarily from zinc mining. China has 60-70% of the world's indium smelting capacity. Indium's price fluctuates wildly and currently the metal trades for $580 per kilogram. Zinc contracts on the LME changed hands for $1,895 per tonne on Friday.

Renewables were up from 0.7% of global energy consumption in 2010 to 2.1% in 2011. Solar power increased 86.3% and at current growth rates solar could provide nearly 10 percent of the world’s electricity by 2018.

One of the world's largest unexploited resources of indium is the Malku Khota deposit in Bolivia. South American Silver's mining project there has been the scene of violent clashes between authorities and local indigenous people which turned fatal this week.