Researchers at the University of California-Los Angeles (UCLA) have developed a way to make tandem solar cells at low cost.
Solar energy is considered a very efficient option when it comes to renewable energy. Although this is not the truth because the current state of the art technology does not change even half of the solar energy required as input. The technology has been adapted to various applications such as satellite and industrial applications but making it more efficient will increase its adaptability to various modern technologies.
An international team of researchers at the University of California-Los Angeles (UCLA) has developed a way to use perovskite in solar cells while protecting it from conditions that cause it to deteriorate. the scientists added small amounts of ions – electrically charged atoms – of a metal called neodymium directly to the perovskite. They found that not only was the grown perovskite more stable when exposed to light and heat, but also that it converted light to electricity more efficiently.
Halide perovskite’s ability to convert light into electricity is due to the way its molecules form a repeating grid of cubes. That structure is held together by bonds between ions with opposite charges. But light and heat tend to cause negatively charged ions to escape from the perovskite, which can damage the crystal structure and reduce the material’s energy conversion properties.
The neodymium ions are just the right size to fit inside a cubic perovskite crystal, and they carry three positive charges, which scientists hypothesize help hold the negative ones. charged ions in the area. The researchers added about eight neodymium ions for every 10,000 perovskite molecules and then tested the material’s performance in solar cells. Working at maximum power and exposed to continuous light for more than 1,000 hours, a solar cell using augmented perovskite retains about 93% of its efficiency in converting light into electricity.
In contrast, a solar cell using standard perovskite loses half of its power conversion efficiency after 300 hours under the same conditions. A device using perovskite with neodymium retained 84% of its power conversion efficiency after more than 2,000 hours, while a device with standard perovskite did not retain its efficiency after that amount of time.
To test the material’s ability to withstand high temperatures, the researchers heated solar cells with the same material to about 180 degrees Fahrenheit. The perovskite-enhanced solar cell retains about 86% of its efficiency after more than 2,000 hours, while a standard perovskite device completely loses its ability to convert light into electricity in that time. time.
Reference: “Suppression of ion migration in metal halide perovskite by interstitial doping with trace amounts of multivalent cations” by Yepin Zhao, Ilhan Yavuz, Minhuan Wang, Marc H. Weber, Mingjie Xu, Joo-Hong Lee, Shaun Tan , Tianyi Huang, Dong Meng, Rui Wang, Jingjing Xue, Sung-Joon Lee, Sang-Hoon Bae, Anni Zhang, Seung-Gu Choi, Yanfeng Yin, Jin Liu, Tae-Hee Han, Yantao Shi, Hongru Ma, Wenxin Yang , Qiyu Xing, Yifan Zhou, Pengju Shi, Sisi Wang, Elizabeth Zhang, Jiming Bian, Xiaoqing Pan, Nam-Gyu Park, Jin-Wook Lee and Yang Yang, 17 November 2022, Nature Materials.