The Korea Institute of Energy Research and UNIST researchers have set the world's highest efficiency record for perovskite solar cells. Perovskite solar cells are next-generation cells that are expected to significantly lower the cost of solar power generation. The research results were published on April 5 in Nature, the most prestigious international scientific journal.
The research team of Dr. Dongseok Kim of Korea Institute of Energy Research and Professor Jinyoung Kim of UNIST developed a perovskite solar cell with an efficiency of 25.6% converting sunlight into electricity in cooperation with researchers at the University of Lausanne (EPFL) in Switzerland. It is the highest among the perovskite solar cell efficiencies officially reported in the paper. The key material for the battery is a synthetic compound called perovskite, which the researchers changed the material combinations in a new way to increase efficiency. This research is expected to be helpful in the development of photoelectric devices such as next-generation displays using perovskite.
In order to improve the efficiency and durability of the perovskite battery, there is active research to improve the performance of the perovskite material itself. This material is a combination of one type of anion and two types of cations, and research between them has been focused on changing the combination of cations.
The joint research team improved battery efficiency and durability by replacing some of the anions (solution content of 2%) that make up the perovskite with a material called formate (HCOO-). This material helps the regular three-dimensional structure inside the perovskite material to grow firmly. The three-dimensional structure is formed by the bonding of ions in the material because the formate interacts with the metal cation to strengthen the bonding force. If you use a material (material with excellent crystallinity) that has a regular three-dimensional structure, the battery efficiency is good. In fact, the efficiency was improved by more than 10% compared to the perovskite battery without the formate added.
UNIST Professor Kim Jin-young (Department of Energy and Chemical Engineering) said, we broke the stereotype that only iodine (I-) or bromine (Br-) ions can be used for negative ions.
Korea Institute of Energy Research, Dong-Seok Kim (Director of Research and Development Center for Next-Generation Battery), Ph. Dr. Dong-Seok Kim said, by designing and manufacturing a solar cell with a structure that can maximize efficiency with the developed material, we have secured a high 25.2% (official certification from Newport). It would be advantageous for commercialization as it is possible to make the product.
Dr. Dongseok Kim's team has been conducting joint research with Professor Jinyoung Kim's team since 2013. On the other hand, perovskite is a material that is also studied in the fields of displays (light-emitting devices) and sensors because it is easy to synthesize and is inexpensive.
The first author, Dr. Jae-Gi Jeong (currently at Lausanne Institute of Technology), said, it is also of great academic significance in that it was the first in the world to discover that formate can interact with surrounding elements at the site of anions in perovskite crystals. The research suggests a new direction for the study of perovskite materials.