Thursday, July 18, 2024

Researchers develop new solar cell with over 26% efficiency

Solar energy is one of the cheapest and most accessible forms of energy. Now, it will be more efficient than ever.

Researchers from a Chinese solar technology company, LONGi Green Energy Technology, have developed a new type of solar cell that could be a game-changer in the world’s transition towards renewable energy.

The new solar cell is made of the same material as 95% of all current solar cells but performs much better at 26.81% efficiency. The innovation further cements the crucial role of solar cells in the energy transition.

This breakthrough is the result of a unique international collaboration between LONGi together with Sun Yat-Sen University (SYSU) and Delft University of Technology (TU Delft).

The research team optimized the design of the solar cell by using a much improved “nanocrystalline-silicon hole contact layer.” The new layer can transfer electricity with far less resistance and results in a higher power conversion efficiency than any other type of solar cell made from crystalline silicon. LONGi researchers developed this new technology on standard, industry-grade silicon wafers, which makes the technology almost immediately applicable in the production of solar panels.

The improvement in cell performance is impressive compared to previous technologies, demonstrating an absolute leap forward in conversion efficiency of 1.5%. “This tops the performance of all other crystalline silicon solar cell architectures to date, which accounts for more than 95% of solar cells produced worldwide,” says Xixiang Xu, vice president of LONGi Central R&D Institute.

SYSU scientists analyzed and studied the exact flow of electricity through the new layers. They found that the cells with the new layers conducted electricity better because they had a low activation energy if they were positioned just right. The bulk Auger process gradually takes the leading role as surface recombination recedes in highly passivated silicon heterojunction solar cells. In other words, the achieved quality of the surface passivation is so high that fill factor and power conversion efficiency can be propelled forward.

The demonstration of this solar cell architecture significantly accelerates the energy transition with the deployment of more efficient photovoltaic modules.

Journal reference:

  1. Hao Lin, Miao Yang, Xiaoning Ru, Genshun Wang, Shi Yin, Fuguo Peng, Chengjian Hong, Minghao Qu, Junxiong Lu, Liang Fang, Can Han, Paul Procel, Olindo Isabella, Pingqi Gao, Zhenguo Li, and Xixiang Xu. Silicon heterojunction solar cells with up to 26.81% efficiency achieved by electrically optimized nanocrystalline-silicon hole contact layers. Nature Energy, 2023; DOI: 10.1038/s41560-023-01255-2