US researchers create low-cost solar paint using quantum dots

A team at Notre Dame University’s Center for Nano Science and Technology (NDnano) in Indiana — headed by Prof Prashant Kamat — devised a technique for creating the solar paint.

‘By incorporating power-producing nanoparticles, called quantum dots, into a spreadable compound, we’ve made a one-coat solar paint that can be applied to any conductive surface without special equipment,’ said Kamat.

The method involved nano-sized particles of titanium dioxide, which were coated with either cadmium sulphide or cadmium selenide. The particles were then suspended in a water-alcohol mixture to create a paste.

When the paste was brushed onto a transparent conducting material and exposed to light, it created electricity with an efficiency of one per cent — some distance behind the typical 10–15 per cent efficiency of commercial silicon solar cells.

Neverthless, Kamat said: ‘This paint can be made cheaply and in large quantities. If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future.’