Jinko’s Perovskite PV Progress – Another New Record

Chinese solar manufacturer JinkoSolar has claimed another world record for solar efficiency, this one related to development of its N-type monocrystalline TOPCon-based perovskite tandem solar cell.

There’s a bit of technobabble to unpack in the type of solar cell involved, so a very quick explainer for starters:

• N-type: A type of cell with a base that has a negative charge. The base of P-type cells have a positive charge. Learn about the difference between P-Type and N-Type cells here.
• Monocrystalline: cut from a single large crystal of silicon.
• TOPCon: Tunnel Oxide Passivated Contact – a solar cell structure using a thin layer of silicon oxide to prevent charge carrier recombination (a key loss mechanism).
• Perovskite: A calcium titanium oxide mineral with semi-conductor attributes. Perovskite also be synthetically manufactured using low-cost fabrication methods.
• Tandem: Multiple solar cells made of different materials stacked on top of each other that combined capture more of the solar spectrum.
• Solar cell: I reckon you know this one.

JinkoSolar says its cell has achieved a conversion efficiency of 33.84%, surpassing the firm’s previous record of 33.24%. It doesn’t seem like much of a bump up, but this is how solar PV technology evolves – a lot of incremental improvements over time. Jinko says the performance of the cell was independently tested by the Shanghai Institute of Microsystem and Information Technology at the Chinese Academy of Sciences.

The company’s N-type monocrystalline TOPCon solar cell, with enhancements, was used as the bottom cell, with the perovskite layer on top.

“This achievement highlights the compatibility of TOPCon as a mainstream solar cell technology with the next-generation perovskite/silicon tandem cell technology, paving the way for new possibilities in the future development of the photovoltaic industry,” said the firm.

JinkoSolar says the latest achievement marks the 27th time it has set a world record for efficiency and power output for PV products.

Perovskite Solar Panels On Home Rooftops – When?

Perovskite materials have been touted as the next big thing for solar for what seems like forever. A major challenge has been degradation – not something you want in a product that’s going to be sitting on a rooftop under all sorts of conditions for what should be decades. But that seems to have been addressed for the most part and tandem cell structures have been a key development.

Back in July last year, we wrote about perovskite solar panels in general and when we might see them commercially available for the home market. So, what’s happened since?

As the boffins keep chipping away with research and refinements, some companies are well under way in gearing up for large-scale commercial production.

One of the leaders is the UK’s OxfordPV, which has been focused on tandem perovskite tech since 2014 and has a pilot production line in Germany. In September last year, the company sent out its first commercial shipment to a U.S-based customer for a utility-scale installation. These panels had a 24.5% module efficiency.  Just as a comparison, high-end conventional panels are currently achieving around 24%. When the firm might start making panels available for residential installations isn’t clear.

Among other players is China’s GCL. After constructing a hundred-megawatt-scale pilot line in 2021, it started building a gigawatt-scale tandem perovskite production line in Kunshan, Jiangsu province in late 2023. GCL recently completed a funding round to advance the facility; which is expected to be completed this year.

GCL (I think) still holds the world record for the most efficient largest commercial-sized perovskite tandem module, achieving 27.34% with a 2m² panel. Earlier last year, it achieved 26.36% with a 1.71 m² panel.

As for when JinkoSolar might be ready for commercial production of perovskite solar panels, there have been no solid plans announced as far as I’m aware. JinkoSolar is a giant among solar manufacturers – in December last year the company claimed it was shipping 1GW of modules every 4 days and had shipped 300GW of solar panels since it began operations.