| Work Detail |
The addition of an ion pair stabilizer to the perovskite cells allows the coating to be performed in ambient air, simplifying the manufacturing process.
An international team of researchers has announced a major achievement on the path to commercializing perovskite solar cells. Perovskite, a semiconductor material, is the subject of research around the world because of its potential to convert more solar energy into electricity than commonly used silicon, and at a lower cost.
However, solar perovskite production has drawbacks. One of them is that the coating process must be carried out inside a chamber filled with non-reactive gas because otherwise the perovskites react with oxygen, which decreases their performance.
A new article published in the journal Nature Energy , titled “ Inhibition of halide oxidation and deprotonation of organic cations with dimethylammonium formate for air-processed p–i–n perovskite solar cells ” dimethylammonium formate for air-processed p–i–n perovskite solar cells) describes the work done by Jixian Xu and his team at the National Synchrotron Radiation Laboratory of the University of Science and Technology of China. The team discovered that adding dimethylammonium formate (DMAFo) to the perovskite solution before coating could prevent the materials from oxidizing. This discovery allows coating to be released into ambient air instead of having to be inside a box.
Michael McGehee, a professor in the Department of Chemical and Biological Engineering and a member of the Institute for Renewable and Sustainable Energy at the University of Colorado at Boulder, interpreted the results and helped write the article. He told pv magazine that it was the first time DMAFo had been used in perovskite research and that it was useful because it is a reducing agent that prevents the iodide from oxidizing. According to his description, DMAFo was added to the perovskite precursor solution. “It protects the iodide from the solution, allowing the cells to be manufactured in air and greatly prolonging the shelf life of the precursor solution,” explains McGehee.
McGehee acknowledged that coating inside a box is acceptable during the research phase, “but when you start coating large pieces of glass, it becomes increasingly difficult to do it in a box filled with nitrogen,” he said.
The results show that DMAFo perovskite cells alone can achieve an efficiency close to 25%, comparable to the current record efficiency of perovskite cells of 26%.
The additive also improved cell stability, which McGehee said is important for the transition to clean energy.
One problem with perovskite solar cells versus silicon is that they can degrade much faster. The study showed that the perovskite cell made with DMAFo retained 90% of its efficiency after 700 hours of exposure to LED light that mimicked sunlight. In contrast, cells made in air without DMAFo degraded rapidly after only 300 hours.
McGehee noted that longer tests are needed because there are 8,000 hours in a year. “Its too early to say they are as stable as silicon panels, but we are on the right track,” he said.
The teams next step is to develop tandem cells with a real efficiency of more than 30% that are as stable as silicon panels over a period of 25 years.
After a decade of research into perovskites, engineers have built perovskite cells as efficient as silicon cells, which were invented 70 years ago, McGehee explains. “We are taking perovskites to the finish line. If tandems work well, they certainly have the potential to dominate the market and become the next generation of solar cells,” he stated. |
