A new thermoelectric material technology that converts thermal energy into electrical energy has been developed, making it possible to manufacture high-performance thermoelectric thin films using an economically efficient solution process.
Thermoelectric materials convert heat energy such as geothermal energy, industrial production and waste heat, body heat, and solar heat into electrical energy.
The Korea Research Institute of Standards and Science (KRISS) announced on Feb. 20 that senior researcher Shin Ho-sun and a research team led by professor Son Jae-sung of the school of materials science and engineering at Ulsan Institute of Science and Technology (UNIST) developed a highly efficient ultra-thin thermoelectric material by aligning the tin-selenide (SnSe) crystal structure.
Tin and selenide are excellent thermoelectric materials, but it is difficult to control their crystal structure because they exist in a polycrystalline form like a stacked paper. This leads to difficulty in achieving high thermoelectric efficiency. It is expensive to apply high temperature and pressure to the materials, and it is difficult to grow crystal in a desired direction.
The team developed a process to grow tin-selenide in a specific direction. The team first prepared tin-di-selenide thin films and then annealed them to evaporate the selenium atoms and produce tin-selenide thin films. The crystal structure was also aligned, making electrical properties more than 10 times efficient than before.
"This new technology is not only simple and efficient, but also controls the direction of tin- selenide crystals," Son said. "With the technology, we can now manufacture high-performance thermoelectric thin films at low cost, and it will help develop standards for the measurement of ultra-thin film thermoelectric materials," said Shin. The research paper was publishedin Nature Communications.