China’s DAS Solar says it has achieved a world record open-circuit voltage of 742 mV for an n-type solar cell based on tunnel oxide passivated contact (TOPCon) cell technology, with a power conversion efficiency of 26.33%.

China’s National PV Industry Measurement and Testing Center (NPVM) has confirmed the result.

“This achievement sets a record for the highest open-circuit voltage of crystalline silicon homojunction solar cells,” the company said in a statement. The previous world record of 735 mV had been reported by Das Solar in December.

The cell has an area of 333.4 cm2 and is based on passivating contacts based on polysilicon and silicon monoxide (SiOx), which reportedly reduce carrier recombination at the metal/silicon interface, thus improving short-circuit current and fill factor.

“DAS Solar's R&D team has consistently improved the open-circuit voltage of TOPCon cells, progressing from 701 mV with TOPCon1.0 to 742 mV with TOPCon4.0 Plus. A perfect passivation structure in the cell underpins its ability to achieve high open-circuit voltage. The TOPCon technology is expected to progress towards its theoretical limit of 28.7% in the near future.” said DAS Solar CTO, Song Dengyuan.

Das Solar is based in headquartered in Quzhou City, Zhejiang province, and currently has an annual TOPCon solar module capacity of 30 GW. Its two largest shareholders are China Huaneng Group and China Merchants Group.

by pv-magazine