Solar cell enables low-cost energy

Researchers at IBM have built a solar cell that set a world record for efficiency and holds the potential for enabling solar cells to produce more energy at a lower cost.

Comprised of copper (Cu), tin (Sn), zinc (Zn), sulphur (S) and/or selenium (Se), the cell’s power conversion demonstrates an efficiency of 9.6 per cent – 40 per cent higher than the value previously attained for this set of materials.

The solar-cell development also sets itself apart from its predecessors as it was created using a combination of solution and nanoparticle-based approaches, rather than the popular, but expensive, vacuum-based technique.

The production method is expected to enable much lower fabrication costs, as it is consistent with deposition techniques including printing, dip and spray coating and slit casting.

Currently available thin-film solar-cell modules based upon compound semiconductors operate at nine to 11 per cent efficiency levels and are primarily made from two costly compounds – copper indium gallium selenide or cadmium telluride.

Attempts to create affordable, earth-abundant solar cells from related compounds that are free of indium, gallium or cadmium have not exceeded 6.7 per cent, until IBM announced that it had achieved the 9.6 efficiency rating.

IBM does not plan to manufacture solar technologies, but is open to partnering with solar-cell manufacturers to demonstrate the technology.