New world record set for thin-film solar cells

The performance of thin-filmed solar cells has been further improved by the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), which is setting a new world record for the fifth time.

ZSW - Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg – is a leading institute working in applied research for photovoltaics, renewable fuels, battery technology, fuel cells and energy system analysis.

A record of 22.6 per cent efficiency of thin-film solar cells based on copper indium gallium diselenide (CIGS) has just been achieved by ZSW; it is 0.3 per cent more than the previous record established by a Japanese-made cell, and 0.6 per cent more than ZSW’s own previous record three months ago.

The rhythm of advance in the research to increase the efficiency of the cell has improved significantly during the last few years and the percentage of efficiency has gone up more in the last three years –with a 0.7 per cent increase per year on average – than in the previous 15 years – with 0.1 per cent increase per year on average.

The cell that achieved the latest record was made thanks to a co-evaporation method and the manufacturing process was improved compared to the last cell. The Fraunhofer Institute for Solar Energy Systems (ISE) has confirmed the results.

Quick advances in research and development could make thin-film cells a serious contender for the silicon-based solutions that have been mainly used until now for PV, and which still have 1.3 per cent lead on thin-film cells.

Prof. Michael Powalla, ZSW board member and Head of the Photovoltaics division said: “I expect that we can achieve up to 25 percent efficiency in the years ahead.”

ZSW will collaborate during the next months with its industry partner Manz AG, a mechanical engineering firm based in Reutlingen, in order to make this latest advance a reality and take the cell from the lab into the factory.