37th EU PVSEC, 07 - 11 September 2020

7 December 2016

Heterojunction Solar Cells – A High-Efficiency Technology With Huge Potential

For years, heterojunction-based silicon solar cells have scored high in efficiency rankings. The well-known HIT cell from Panasonic reached a world record 25.6% efficiency in early 2014, according to the solar cell efficiency tables edition of Progress in Photovoltaics, -  and has kept this record for over 2.5 years.

The reason for Panasonic’s dominance is simple – Sanyo (which was overtaken by Panasonic) developed the crystalline silicon heterojunction cell concept, has been mass-producing it, and protected the intellectual property. But Sanyo’s patents expired in 2010. Since then the race is on, with several PV module companies and equipment manufacturers working on product solutions for heterojunction cells.

Heterojunction cell technology not only offers high efficiencies; it also offers a very compact production set up. The core of heterojunction processing relies on PECVD tools to deposit a-Si layers and PVD tools for applying TCO. This process sequence only needs 6 process steps compared to 9 with standard technology.

The dramatic decrease in cost and price for standard silicon cells in the last few years has made it very difficult for new solar cell technologies to get a foot into the mass market. But Meyer Burger from Switzerland, a strong advocate of heterojunction cells and the only provider of a turnkey solution for this technology, has just bagged a major order. In November, the PV production equipment manufacturer has signed an agreement with a customer in Turkey to install a 200 MW fully-integrated PV manufacturing unit based on heterojunction cell technology. Delivery of the equipment is scheduled for the third quarter of 2017, production ramp up expected to commence in first quarter of 2018. According to Meyer Burger, this unidentified customer has already plans to expand production capacity to 1 GW within 5 years.

While Meyer Burger is currently the only PV equipment company offering a turnkey line for heterojunction modules, there are other suppliers offering key deposition tools for HJT cells.  Another European equipment supplier, Singulus from Germany, announced in October that it will use funds from a capital increase, among others, “to create new product solutions to tap the growth in the field of crystalline high-performance solar cells (heterojunction).” Already in August, Singulus had signed a memorandum of understanding with Chinese companies GCL, the world’s largest silicon and wafer manufacturer, and CIE, which has specialized in the development of high-efficiency HJT cells. Singulus will assume “the task of developing, optimizing, building and supplying the appropriate production systems for the manufacturing of HJT solar cells.“

In fact, the leading European solar research institutes are quickly progressing with their HJT cell developments, almost any of the world’s leading cell manufacturers has HJT on its technology roadmap, the market potential is simply huge – and those jumping on the train early are starting to see their first fruits.

Japanese company Kaneka Corporation, which has a solar cell research collaboration agreement with Belgian research institute IMEC since 2009 that was extended for another 3 years end of 2015, just announced a new world record for solar cells. Kaneka released in September that it was able to produce a 26.33% efficient cell, based on a combination of heterojunction technology and back-contact cell design. This 180 cm2 large record cell, measured by Fraunhofer ISE, not only broke the prior record by 0.7 percentage points, it is the first non-concentrated silicon solar cell that has a conversion efficiency higher than 26%.

Panasonic, on the other hand, has just signed a letter-of-intent with Tesla to cooperate on cell and module production in a facility in Buffalo, New York, where US company SolarCity has been building cell lines based on heterojunction technology. The $900 million factory, which would be operated by Panasonic and is planned to start production in mid-2017, would supply Tesla/SolarCity with cells and modules.

EU PVSEC addresses a dedicated session to heterojunction technology

EU PVSEC is responding to the increased activities in heterojunction solar technology. Starting with our 33rd edition in Amsterdam from 25-29 September 2017, heterojunction will be a topic under the Silicon Photovoltaic Topic in the program. We are looking forward to receive many paper applications on HJT. And we also invite companies to present their HJT products at our exhibition.