Significant efficiency increase for PERC cells

A technology alliance between Roth & Rau AG, a member of the Meyer Burger Technology Group, and InnoLas achieves increased efficiency in industrial solar cell production by one percentage point Meyer Burger (SIX Swiss Exchange: MBTN) Group member Roth & Rau AG (Frankfurt Exchange: R8R) and InnoLas Systems GmbH have installed upgraded PECVD systems and lasers for PERC (Passivated Emitter and Rear Cell) solar cells at several customers, thereby significantly increasing the efficiency of standard monocrystalline cells by up to one percentage point. The process, including both upstream and downstream process steps, was developed by Roth & Rau and InnoLas in close cooperation with end customers and verified in running production lines.

InnoLas Managing Director Richard Grundmüller: “It is crucial that we achieved this increased efficiency in industrial production lines and not only under laboratory conditions. In recent months, our technology has proven itself to be very robust and can now be integrated into existing production lines.”

A Roth & Rau MAiA PECVD system has been used for rear surface passivation with aluminium oxide and silicon nitride, and an InnoLas Systems ILS TT for laser contact opening. This combination of systems achieved line throughputs of up to 3,400 wafers per hour which meets the throughput requirements of ultra modern industrial mass production of solar cells. The higher efficiency represents a significant competitive advantage for cell manufacturers.

Roth & Rau Head of Sales Thomas Hengst: “We have integrated the two coating processes required for rear surface passivation into the tried and tested SiNA/MAiA platform. The modular design ensures optimum process flexibility and throughput variability, enabling the configurations to be easily adapted to existing requirements and operating costs to be cut further. The application of the AlOx and SiN cap layers increases process safety whilst maintaining the vacuum. Moreover, this eliminates the need for additional handling, giving a corresponding boost to the yield. Both Roth & Rau and InnoLas possess comprehensive know-how in the implementation of stable and efficient best-in-class technologies.”

The overall technology developed by Roth & Rau and InnoLas Systems is also designed to be easily integrated into existing production lines as well which thus extends the innovative system portfolio in photovoltaic technology offered by the Meyer Burger Group. Several installations incorporating this technology are currently in preparation for leading manufacturers.

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Acknowledgements

Solar Media