New record-breaking thermoelectric material

◦ Prof. In Chung’s group at Seoul National University announced the development of the new record-breaking thermoelectric material consisting of less-toxic and inexpensive elements on Aug. 3 (Tue).

◦ Greater than 65% of the produced energy worldwide is lost as waste heat. Electric energy is mostly generated from fossil fuels. Accordingly, recovering such a huge amount of ubiquitous energy loss into usable forms of energy can contribute to solving energy and environmental crisis that humanity faces.

 

◦ Thermoelectric technology can contribute to solving such problems simultaneously. It converts heat to electric energy directly without releasing any environmentally undesirable chemical residues like greenhouse gases. However, current high-performance thermoelectric materials typically contain toxic lead and/or rare tellurium element, and their power generation efficiencies are low, making it difficult commercialize this technology.

◦ Prof. Chung’s group solved all these problems by developing a new ultrahigh performance polycrystalline thermoelectric material consisting of tin and selenium elements. Tin selenide-based material has attracted explosive academic attentions in 2014 because of the strikingly high thermoelectric figure of merit (ZT) of 2.6 reported in its single crystal form. However, the reproducibility of such high performance has been controversial so far. Futhermore, the corresponding polycrystalline materials have performed much poorer. Indeed, single crystal forms are unsuitable to mass production and commercial applications due to the high cost, lengthy and labor-intensitve production and mechanical brittleness.

◦ Prof. Chung’s group revealed the origin of poor performance of polycrystalline tin selenide materials, and developed a new synthesis process to solve all problems. As a result, the obtained new polycrystalline material exhibits thermoelectric figure of merit greater than 3.1 in a bulk form for the first time in history. Its record-breaking thermoelectric power generation efficiency exceeds 20%.

◦ Prof. Chung emphasized that “our new material open an era of the commercialization of ultrahigh performance practical thermoelectrics” like perovskite materials changing the paradigm of solar cell researches. Prof. Chung had also developed all-solid-state solar cells based on perovskite materials for the first time in 2012.

◦ This research result was published in the latest online edition (Aug. 3) of ‘Nature Materials’. This work was supported by Nano Material Technology Development and Mid-Career Research Programs throught the National Research Foundation of Korea grant funded by the Korean Government.

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