Longi sets new record for silicon-perovskite tandem solar cell efficiency

Chinese solar PV manufacturer Longi has set a new world record efficiency of 30.1 per cent for the commercial M6 size wafer-level silicon-perovskite tandem solar cell.

LONGi announced the record last week at the 2024 Intersolar Europe conference in Munich, Germany, as a “key milestone” towards the industrialisation of tandem PV technology.

The record, achieved by the team at the Longi Central R&D Institute,  was independently certified by the Fraunhofer Institute for Solar Energy (Fraunhofer ISE).

“[The team] started research on mass production technology for tandem solar cells in October 2023, and in just six months, they overcame two key challenges: the preparation of large-area perovskite films in air and ultra-low-temperature metallization,” said Dr He Bo, research and development director at the Institute.

Longi says the new record delivers a “significant efficiency advantage” over the recent 27.3 per cent efficiency record it set for silicon heterojunction back-contact (HBC) solar cells and “greatly boosts” confidence in tandem technology.

The new record also cements Longi as a leader in crystalline silicon photovoltaics, with the company holding the efficiency record for both crystalline silicon solar cells and for crystalline silicon-perovskite tandem solar cells.

Solar efficiency records such as this come in several flavours, with an efficiency record for a solar cell different than that achieved for a commercial wafer-level cell.

This latest record, then, came a week after LONGi announced a new world efficiency record of 34.6% for silicon-perovskite tandem solar cells.

This new record also serves to break the previous world record of 28.6% wafer-level tandem solar cell efficiency on M4 commercial size wafers in May 2023 with an absolute efficiency advantage of 1.5%.