The Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) has achieved a record 20.8% conversion efficiency with a copper indium gallium diselenide (CIGS) thin-film PV cell.

This beats the official record for a multicrystalline PV cell, which stands at 20.4%.

Michael Powalla, head of the photovoltaics division at ZSW, said: "Our new record shows that CIGS thin-film technology still has untapped technological and economic potential.”

ZSW had held the previous CIGS record of 20.3% on glass. The results have been officially confirmed by the Fraunhofer Institute for Solar Energy Systems ISE.

According to Powalla, using a CIGS simultaneous evaporation process will make scaling to volume production much easier. ZSW is now working to transfer the optimised CIGS process to modules.

"It may take a little time for the higher efficiency to be reflected in production," he said. "But 16 to 18% in commercial modules is possible over the next few years."

Market-standard CIGS modules currently attain efficiencies of 14 to 15% - a module always has lower efficiency than an individual solar cell, noted Powalla.