IBM makes 9.6 per cent efficient PV cell from earth-abundant materials

• 14 years ago (2010-02-12)
• David Flin

North America 996 Renewables 751

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IBM claims to have developed a thin-film photovoltaic cell with high efficiency where the key absorbing layer is made entirely of readily available elements. The company claims that this new development offers the potential for solar cells to produce more energy at a lower cost.

Existing thin-film solar modules based on compound semiconductors operate with solar-to electrical energy conversion efficiency of 9-11 per cent. However, these are made of costly materials or contain elements whose scarcity could limit production, or have poor prospects for improving efficiency further.

To bypass potential supply problems associated with current devices, IBM’s aim was to create more affordable solar cells from related compounds of more abundant elements. However, previous attempts had not exceeded 6.7 per cent efficiency. By contrast, IBM’s new solar cell is claimed to have a conversion efficiency of 9.6 per cent, comparable with current commercially available thin-film solar cells.

The new CZTS solar cell has an absorbing layer consisting of copper (Cu), zinc (Zn), tin (Sn), sulphur (S) and/or selenium (Se). It is created using a composite liquid deposition approach that merges the concepts of both solution and nanoparticle-based coating, rather than using prevalent but expensive vacuum-based techniques. IBM expects this change in production technique to enable much lower fabrication costs, as it is consistent with high-throughput and high material utilisation-based deposition techniques, including printing, dip and spray coating and slit casting.

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