‘New World Record’ For Highest Voc Of TOPCon Cells

• DAS Solar has reported a peak efficiency of 26.24% for its n-type TOPCon cell for 333.05 cm² area
• It uses self-developed TOPCon 3.0 plus technology that comprises i-SE, ultra-thin polycrystalline silicon and micro-doped ut-PolySi technologies
• The company has also announced achieving open-circuit voltage of 730mV which it claims is a new world record

Chinese solar cell and module manufacturer DAS Solar has announced achieving peak efficiency of 26.24% for its n-type TOPCon cell of M10 size on an area of 333.05 cm² using its self-developed TOPCon 3.0 plus technology while claiming a 'new world record' for the highest Voc of TOPCon cells.

The open circuit voltage Voc it achieved was up to 730mV for 333.05 cm². The TOPCon 3.0 Plus cell uses the company's proprietary i-SE, ultra-thin polycrystalline silicon and micro-doped ut-PolySi technologies.

The cell is also equipped with a 'new' type of emitter layer surface passivation technology called mt-Pass that significantly lowers the emitter's recombination current, bringing the passivation effect close to the backside of SiO2/PolySi passivation technology, it explains.

The manufacturer believes this cell structure can help it achieve an open-circuit voltage of over 736mV, and the efficiency of the cell can reach over 27%, as per its computer theoretical model simulation.

DAS says it has received the latest certification report from the quality testing center for solar PV and wind power systems at the Chinese Academy of Sciences Institute of Electrical Engineering.

According to the team, the Voc achieved is higher than open circuit voltage of 724.9mV earlier reported by the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) for n-type TOPCon cells with a double-sided electrode structure.

"The achievement of an open-circuit voltage as high as 730mV for DAS Solar's TOPCon cells indicates a significant breakthrough in the development of passivation technologies, which holds great significance for the continuous improvement of TOPCon cell efficiency," said DAS Solar's CTO Dr Song Dengyuan who is also an expert with the National Key R&D Program of China on Renewable Energy and Hydrogen Technology.

Speaking at TaiyangNews Solar Module Innovations Conference in January 2023, Dr Dengyuan Song, CTO, DAS Solar discussed the development of n-type TOPCon multi-GW level module production of the company with high power and low degradation. Sharing the company's technology and production roadmap in 2023, Song said DAS Solar will target to further improve the cell efficiency of its DAON cell to 25.8%, up from 25.2% in 2022. The cell efficiency of its DAON cells in mass production at that time stood at 25.2% and for modules it is 22.8% (see presentation here).

DAS Solar's TOPCon module with 22.3% efficiency and another PERC product with 21.7% efficiency are listed on TaiyangNews' latest Top Solar Modules Listing (see Top Solar Modules Listing—April 2023).