The research team led by Professor Meng Qingbo at the Institute of Physics, Chinese Academy of Sciences has achieved another breakthrough in the field of new thin-film photovoltaics. The team has raised the certified power conversion efficiency of copper zinc tin sulfur selenide (CZTSSe) cells to 16.6% and successfully developed high-performance flexible cells and modules. This marks the 10th time they have set a new world record in this field, signifying that China now takes a global lead in new-generation photovoltaic technology and has crossed the key threshold for industrialization.
CZTSSe is an emerging thin-film photovoltaic material. It is mainly made from abundant, low-cost elements such as copper, zinc, and tin. It is environmentally friendly and highly resistant to space radiation. Thanks to these advantages, the material is regarded as a promising candidate for large-scale applications on Earth and in space. It is especially suitable for major projects including low-Earth orbit satellites and space-based energy stations, perfectly meeting their core demands for solar technology: low cost, long service life, and light weight.
“Despite its clear strengths, CZTSSe photovoltaic technology has stagnated over the past decade. With multiple constituent elements, the material easily suffers from complex defects, disordered atomic arrangement, and high internal energy loss, which hindered cell performance and industrial progress.” Meng noted.
To solve these problems, Meng and his team overcame critical technical challenges, including material crystallization, atomic structure regulation, and defect control. They proposed an “atomic vacancy” strategy that directs the ordered arrangement of copper and zinc atoms, reducing defect activity and internal energy loss at the source.
In 2022, Meng’s team was the first to break the 13.0% efficiency bottleneck for CZTSSe cells. Over the next three years, the team successively pushed efficiencies to 14.0%, 15.0%, and finally 16.0%. They also completed the development of high-performance flexible cells and modules. The related achievements were selected as one of China’s Top 10 Photovoltaic Scientific Advances in 2023. Since 2023, the team has published five consecutive papers in the journal Nature Energy.
Based on the development pattern of thin-film photovoltaics, technologies with efficiencies between 15.0% and 16.0% are ready to enter industrialization. With a conversion efficiency of 16.6% and inherent material advantages, CZTSSe technology has now passed the critical industrialization threshold.
Industry experts predict that the technology will become fully competitive once cell efficiency approaches 20.0%, module efficiency reaches 18.0%, and mass production is realized. It is expected to be widely used in aerospace equipment, supporting China’s “dual carbon” goals and space power strategy. Meng stated that his team will strengthen basic research, accelerate technology development, and collaborate with partners to speed up industrialization, providing Chinese solutions for the global clean energy system.