b'Carnegie Science|Spring/Summer 2020 15Lakes HaveThermoelectric More-SevereGenerators Could Possibly Fight Algal Blooms Worldwide Climate ChangeP ressure improves the ability ofother processes, making major materials to turn heat intocontributions to the nations energy budget.electricity and could potentiallyHowever, engineers have been unable be used to create cleanto improve the room-temperature generators, according to new work from aperformance of any thermoelectric team that includes Carnegies Alexandermaterials in 60 years, meaning that Goncharov and Viktor Struzhkin, formerlydevices built to take advantage of thispublishedThis artwork is a conceptual representation of how with Carnegie. Nature Materials capability are only practical for some very applying pressure in the diamond anvil cell changes the the work. specific applications, including remote gaselectronic structure of lead selenide. Alternative energy sources are key topipelines and spacecraft. Image courtesy Xiao-Jia Chen, Center for High Pressure Science and combating climate change caused byOur measurement of the efficiency ofTechnology Advanced Researchcarbon emissions. Compounds withroom-temperature thermoelectricity has thermoelectric capabilities can convertnot budged in more than half a century,that material science is suited to address.thermal energy, which is innate and has asaid Goncharov. ThermoelectricThe research teamled by Liu-Cheng physical need to spread from a hot placecompounds have demonstrated improvedChen of the Center for High Pressure into a cold place, into energyharvestingperformance at high temperatures, but weScience and Technology Advanced electricity from the temperaturereally need them to work well at roomResearchfound that they could improve differential. In theory, generators built fromtemperature to make the most of theirthe thermoelectric capability of lead these materials could be used to recoverpotential for green energy. selenide by applying pressure and mixing electricity from wasted heat given off byThis is precisely the kind of problemin charged particles of chromium. By squeezing the material in the diamond anvil cellwhich acted as a sort of chemical pressureand adding the chromium, the lead selenide was encouraged to undertake a structural rearrangement, at the atomic level, enabling the most efficient demonstration of room-temperature thermoelectric generation ever recorded.Under 30,000 times normal atmospheric pressure, the chromium-doped lead selenide was able to produce electricity with the same efficiency that the top-performing thermoelectric materials do at 80F (27C).Our work presents a new way to use compression techniques to improve the thermoelectric performance, bringing us closer to practical applications that could help fight climate change, concluded Xiao-Jia Chen of the Center for High Pressure Science and Technology Advanced Research and formerly of Carnegie.COAUTHORS:The papers other coauthors are Pei-Qi Chen of MIT, Wei-Jian Li Alex Goncharov (left), coauthor on the study, is shown in his Carnegie lab with colleagues.and Xiao-Jia Chen of the Center for High Pressure Science and Technology Advanced Research, and Qian Zhang and Zhifeng Image courtesy Carnegie Institution for Science Ren of the University of Houston.'