Recently, LONGi Green Energy Technology Co., Ltd. (hereinafter referred to as "LONGi") published a research paper titled "Perovskite-silicon tandem solar cells with bilayer interface passivation" online in the journal Nature as the first corresponding author. The paper publicly reported the research results of breaking through the efficiency limit of single-junction solar cells by developing crystalline silicon-perovskite dual-junction tandem solar cells.
The dual-junction tandem solar cells are considered to have the potential to exceed the theoretical efficiency limit of single-junction solar cells in terms of photovoltaic conversion efficiency. For decades, research institutions and teams worldwide have been committed to achieving this goal.
In November 2023, LONGi, a China-based solar technology company, announced that its crystalline silicon-perovskite tandem solar cell has been certified by the National Renewable Energy Laboratory (NREL) with an efficiency of 33.9%. This achievement sets a new world record for the efficiency of this type of cell and surpasses the Shockley-Queisser limit of single-junction semiconductor photovoltaic materials.
This study employs a double-layer staggered passivation strategy, which more effectively suppresses the non-radiative recombination at the perovskite interface while ensuring efficient charge transport. Additionally, to better achieve structural coupling between the perovskite top cell and the crystalline silicon bottom cell, LONGi independently developed a patented technology for silicon heterojunction solar cells with an asymmetric textured surface. The front surface of this silicon cell has a fine textured surface, facilitating the solution-based preparation of perovskite film, while the rear surface of the silicon cell uses a standard large size textured surface to achieve better passivation and infrared spectral response.
Through a series of key technological breakthroughs, LONGi's tandem team has achieved a certified conversion efficiency record of 33.9% for ultra-high-efficiency perovskite/crystalline silicon tandem solar cells. This is the first time in the history of global solar cell development that the efficiency of tandem solar cells has been experimentally proven to exceed the Shockley-Queisser efficiency limit of single junction solar cells, marking a milestone achievement.
The work also received strong support and assistance from the co-corresponding agencies, including Soochow University, Clean Energy Research Institute of China Huaneng, and the Hong Kong Polytechnic University.
In recent years, LONGi has maintained intensive R&D activities in the field of crystalline silicon-perovskite tandem solar cells, continuously achieving breakthrough progress. Currently, the two-terminal tandem prototype devices (1 square centimeter) developed by LONGi's tandem team have been authoritatively certified with the record efficiency of 34.6%. The commercial-sized two-terminal tandem cells developed for mass production (M6) and the world's first square meter four-terminal tandem modules have been authoritatively certified with efficiencies of 30.1% and 25.8%, respectively. These results demonstrate a significant efficiency advantage over single junction silicon cell technology. This has greatly boosted the global photovoltaic industry's confidence and expectations for the next generation of ultra-high-efficiency tandem photovoltaic power generation technology.
About LONGi
Founded in 2000, LONGi is committed to being the world’s leading solar technology company, focusing on customer-driven value creation for full scenario energy transformation.
Under its mission of 'making the best of solar energy to build a green world', LONGi has dedicated itself to technology innovation and established five business sectors, covering mono silicon wafers cells and modules, commercial & industrial distributed solar solutions, green energy solutions and hydrogen equipment. The company has honed its capabilities to provide green energy and has more recently, also embraced green hydrogen products and solutions to support global zero carbon development. www.longi.com