Researchers at University of California-Los Angeles (UCLA) have developed a way to fabricate tandem solar cells at low cost.
Solar energy is considered to be a very efficient option when it comes to renewable energy. Although it is not quite the fact as the current state of the art technology does not convert even half the solar energy it takes as input. The technology is adapted into a variety of applications like satellite and industrial applications but making it more efficient could boost its adaptation into various modern technologies.
An international team of researchers at University of California-Los Angeles (UCLA) have developed a way to use perovskite in solar cells while protecting it from the conditions that cause it to deteriorate. the scientists added small quantities of ions — electrically charged atoms — of a metal called neodymium directly to perovskite. They found not only that the augmented perovskite was much more durable when exposed to light and heat, but also that it converted light to electricity more efficiently.
Halide perovskite’s ability to convert light to 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 pop out of the perovskite, which damages the crystal structure and diminishes the material’s energy-converting properties.
Neodymium ions are just the right size to nestle within a cubic perovskite crystal, and they carry three positive charges, which the scientists hypothesized would help hold negatively charged ions in place. The researchers added about eight neodymium ions for every 10,000 molecules of perovskite 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 the augmented perovskite retained about 93% of its efficiency in converting light to electricity.
In contrast, a solar cell using standard perovskite lost 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 retained none of its efficiency after that amount of time.
To test the material’s ability to withstand high temperatures, the researchers heated solar cells with both materials to about 180 degrees Fahrenheit. The solar cell with augmented perovskite held onto about 86% of its efficiency after more than 2,000 hours, while a standard perovskite device completely lost its ability to convert light to electricity during that time.
Reference: “Suppressing ion migration in metal halide perovskite via interstitial doping with a trace amount 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.