Nanorod deposition method maximises solar-cell absorption

The team of researchers from the Materials and Surface Science Institute (MSSI) at Limerick University said its method is purely solution-based, simply using electrophoresis to line up the all-important nanorods.

‘There are two components to what we’ve done — we’ve managed to synthesise the rods and develop technology to assemble them so they’re all packed together and perpendicular,’ Dr Kevin Ryan of Limerick told The Engineer.

Current silicon-based commercial solar cells are costly to process, whereas alternative technologies rely on toxic materials such as cadmium or tellurium.

The most sought-after materials currently for solar energy conversion are copper-indium-galium-disulfide (CIGS) and di-copper-zinc-tin-tetrasulphide (CZTS).

By combining the four elements in each material in the correct combination, very high conversion of solar energy to electricity can be obtained. CIGS cells have shown the highest-possible efficiencies whereas CZTS, although marginally lower, are regarded in the industry as being equally attractive for large-scale commercialisation as each of the elements are in high natural abundance.