“Compared to the previous results imec reported, we have further optimized the fully screenprinted bifacial n-PERT cell process and adopted a design with twelve busbars. The current cells also have a screenprinted front grid and rear soldering pads that use less silver,”

LEUVEN (Belgium), APRIL 8, 2019 — Today, at SiliconPV 2019, imec, a world-leading research and innovation hub in nanoelectronics and digital technologies and partner in EnergyVille, announces that its n-PERT (Passivated Emitter and Rear Totally diffused) solar cells developed with Jolywood, a leading Chinese manufacturer of n-type bifacial solar cells and modules, have reached a certified front-side conversion efficiency of 23.2 percent. With cost-efficient processing and a clear path to higher efficiencies, this makes these n-PERT cells a serious contender to p-PERC technology.

"Compared to the previous results imec reported, we have further optimized the fully screenprinted bifacial n-PERT cell process and adopted a design with twelve busbars. The current cells also have a screenprinted front grid and rear soldering pads that use less silver," says Loic Tous, project leader at imec/EnergyVille. "The open circuit voltage (Voc) is now above 690mV with fill factors up to 83%. These remarkable results are obtained using the same industry-compatible equipment to produce bifacial p-PERC cells, with the addition of a boron diffusion."
A batch of 12 new M2-sized cells (244.3 cm²) measured at ISFH CalTec showed an average conversion efficiency of 23.0 percent, with the best cell topping 23.2 percent, and our own measurements revealed a bifaciality above 80 percent. Moreover, used under standard front illumination conditions in conjunction with an additional 0.15 sun rear illumination, the cells can achieve an effective conversion efficiency of almost 26 percent. In addition, ISFH Caltec measured an average reverse current of -0.4A (at -12V) indicating excellent breakdown characteristics.
The developed n-PERT technology has a number of inherent advantages over p-type PERC cell technology, which is demonstrated in these newest cells: the potential for higher efficiencies because of a lower sensitivity to metal impurities, and the absence of light induced degradation (LID). Therefore, n-type PERT technology could become a cost-effective contender to p-type PERC cells. To enable this, the current cells have a screenprinted front grid and rear soldering pads which together amounts to less than 80mg of silver used per cell.
Imec and Jolywood are confident that their bifacial n-PERT cells will soon reach efficiencies above 23.5 percent, coupled to a bifaciality above 90 percent.
Jia Chen, R&D director at Jolywood: "Jolywood targets to bring the best solar solution to the market. Devoted to R&D and manufacturing of the world's best n-type cells and modules, we believe n-type technology can contribute to the industry with high performance, high reliability and low LCOE . We have chosen imec to help us reach that target because of their unique expertise and research infrastructure. We are also developing bifacial n-PERT cells with passivating contact technology, and have already achieved efficiencies above 23%. Combining all the technology know-how, we are confident that our bifacial n-type solar cells will achieve an efficiency above 24% very soon."
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About imec
Imec is a world-leading research and innovation hub in nanoelectronics and digital technologies. The combination of our widely acclaimed leadership in microchip technology and profound software and ICT expertise is what makes us unique. By leveraging our world-class infrastructure and local and global ecosystem of partners across a multitude of industries, we create groundbreaking innovation in application domains such as healthcare, smart cities and mobility, logistics and manufacturing, energy and education.
As a trusted partner for companies, start-ups and universities we bring together more than 4,000 brilliant minds from over 85 nationalities. Imec is headquartered in Leuven, Belgium and has distributed R&D groups at a number of Flemish universities, in the Netherlands, Taiwan, USA, China, and offices in India and Japan. In 2017, imec's revenue (P&L) totaled 546 million euro. Further information on imec can be found at www.imec-int.com.
About Jolywood
Jolywood (SZ: 300393) is the world leader in development, production and marketing of PV backsheet, high-efficiency mono-crystalline n-type bifacial solar cells and bifacial modules. Founded in 2008, Jolywood (Suzhou) Sunwatt Co. Ltd. (Jolywood Suzhou) is the largest manufacturer of PV backsheet worldwide, with an annual production capacity of over 100 million meters. Jolywood (Taizhou) Solar Technology Co. Ltd. (Jolywood Taizhou), a wholly-owned subsidiary of Jolywood Suzhou, was founded in 2016 and tops the global solar industry with 2.1GW in manufacturing capacity of N-type bifacial solar cells since 2017. As the world confronts growing challenges of energy and environmental, Jolywood committed to the mission of "Let sunshine 24-hours serving human life", empowering people around the world to go solar by using our manufacturing and development expertise to address unique local energy challenges. For more information, please visit http://www.jolywood.cn/

About EnergyVille
EnergyVille is a collaboration of the Flemish research institutes KU Leuven, VITO, imec and UHasselt in the field of sustainable energy and intelligent energy systems. Our researchers provide expertise to industry and public authorities on energy-efficient buildings and intelligent networks for a sustainable urban environment. This includes, for example, smart grids and advanced district heating and cooling.
One of the objectives of EnergyVille is to become a top of European innovative energy research initiative. In this context, the center was embedded in major national and international networks right from the start. It covers research, development, training and innovative industrial activities under one name and in close collaboration with local, regional and international partners.

EnergyVille aims to be a driver in the Thor science park in Genk in the areas of research, business development and employment creation. The research center is supported by the city of Genk, the Flemish Government, The Province of Limburg, LRM, Nuhma, POM Limburg and the European structural funds.

Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a "stichting van openbaar nut"), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.) and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited), imec Florida (IMEC USA nanoelectronics design center).