A messy perovskite separation


From the outside it looked like the perfect partnership. Two pioneering European PV technology companies at the forefront of crystalline silicon cell production processes and solar cell efficiency, coming together to accelerate the deployment of the most promising step-change technology.

In March 2019, Meyer Burger and Oxford PV entered a “strategic partnership” and “exclusive cooperation agreement” to develop and deploy the technology required to bring perovskite-tandem PV modules to market. The target cell efficiency, to be produced on lines installed at Oxford PV’s production base in Brandenburg, Germany, was 27%. It represented a rebirth of European high-efficiency cell production and a major leap forward for conversion efficiency.

Meyer Burger was to bring its vast experience in developing and deploying solar production equipment, along with 250 MW of heterojunction (HJT) and Smartwire production equipment, to the partnership. It also lent industry credibility to Oxford PV’s endeavors and took an 18.4% stake in the UK-headquartered company. On the other side, the Oxford University spinoff would bring its pioneering perovskite-tandem know-how, which includes a portfolio of some 350 patents, having scaled up perovskite-silicon cells from the size of a computer chip to full-sized cells over the previous decade.

However, sometimes life just gets in the way of even the best-laid plans. On July 23, Oxford PV announced that the installation of the initial 100 MW HJT line provided by Meyer Burger had been completed and, as such, the “exclusive cooperation agreement” had come to an end. Oxford PV CEO Frank P Averdung explained at the time that the “build-out of the factory” and installation of the “entire HJT equipment” had been completed. On this basis, Oxford PV “terminated its exclusive relationship with Meyer Burger” the company announced in a statement.

Irreconcilable differences?

It’s likely there are a confluence of factors behind the parting of the two companies, and the details of the initial partnership remain opaque. Neither Meyer Burger nor Oxford PV took up the opportunity to speak with pv magazine for this article. Indeed, somewhat of a cloak of silence has descended upon the European PV community when it comes to making public comment on the cooperation’s conclusion.

The technology itself appears to be a significant factor behind the split. While it has broad expertise in PV production and once supplied equipment right across the solar cell and module production processes, Meyer Burger appears not to have significant expertise in the processes for perovskite deposition.

While PV perovskites can be deposited through a range of low-cost processes, such as slot die printing, for tandem applications it is likely that physical vapor deposition (PVD) processes, likely magnetron sputtering, are a good fit. Chris Case, Oxford PV’s CTO, would not reveal the processes it is deploying in detail, however he did acknowledge that “it does include sputtering” and that “it is a good process for coating very large areas of thin film.” He elaborated that the equipment Oxford PV is deploying can “hold up to 110 wafers” and coat a wafer “every 1.7 seconds.”

At the same time, the Oxford PV team noted that while Meyer Burger was producing and installing all of the HJT equipment, it was acting as a turnkey supplier for the perovskite tools – indicating that they were being built by a third-party equipment supplier. Given this, it could make sense for Oxford PV to cut out the middleman.

While it is somewhat speculative as to who the perovskite production equipment supplier is, there are a relatively small number of experienced suppliers of the PVD equipment to the solar industry. “If Oxford is sputtering [the perovskite semiconductor] it could make a lot of sense to work with an expert in that area, like Von Ardenne or another supplier that is established in the thin film world,” said industry analyst Alex Barrows, of UK-based Exawatt, in July. “Oxford PV could simply work directly with a sputtering or thin film deposition expert.”

Investor issues

There could also be investor conflicts behind the separation. Meyer Burger became Oxford PV’s largest shareholder in 2019 when the cooperation deal was struck, and former Meyer Burger CEO Hans Brändle took a seat on the U.K. company’s board of directors. However, it did not take up its “option to increase shareholding” to up to 31.6%, which was a part of that original deal. Meyer Burger also made a radical pivot toward becoming a cell and module maker, as confirmed at its ordinary general meeting on May 13, 2020. Furthermore, Oxford PV has other strategic investors that may not have been comfortable with Meyer Burger’s continued involvement.

Another notable investor in Oxford PV is Chinese wind power giant Goldwind. On March 19, 2019, the company “led the investment round D” of Oxford PV to the value of GBP 21 million ($28.6 million). At the time, Goldwind VP Xiao Zhiping issued a statement noting Oxford PV’s “world famous” leadership in perovskite technology. “Goldwind and Oxford PV have a common vision of innovation values and energy transformation. We believe that new energy combinations such as photovoltaic and wind power will usher in broader global development space in the next 20 years,” read the statement.

Whether the involvement of both Meyer Burger and Goldwind as Oxford PV investors could not be sustained in future rounds is unclear, but it is conceivable. Averdung himself said, at the time of the Meyer Burger split, that Oxford PV was “in the final stages of the funding round” that would allow the company to reach gigawatt-scale production – currently planned for 2024.

“There are perovskite companies in China – maybe Goldwind thinks that Oxford PV’s [technology] is better,” said BloombergNEF’s solar head, Jenny Chase, considering the potential development. “Geopolitically it would be an interesting time for Oxford PV to choose a Chinese partner over Meyer Burger, but it could bring much more enthusiasm and capital for short term commercialization.”

There are clearly more questions than answers as to where the split leaves the IP behind Oxford PV’s perovskite tandems and the additional 150 MW of HJT equipment Meyer Burger was to supply, in a deal announced on Oct. 22, 2019. Meyer Burger is “considering legal options,” as of July 23, 2021, as to its next steps. When announcing the potential legal action, the company noted that it believes perovskite tandems will only achieve the required “technology and process maturity, product reliability and cost structure for competitive mass production in a few years.” However, it continued that perovskite tandems are “are an integral part of Meyer Burger’s roadmap.” Separations, it seems, are never easy.

(additional reporting by Vincent Shaw)

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