Student: Katherine Woo, Graduate Student in Chemistry, Iowa State University
Faculty Advisor: Dr. Kirill Kovnir
Thermoelectric materials, which convert heat into electricity, have been used both on Earth and in space. Batteries and solar power are often insufficient to energize deep-space missions, and so thermoelectric generators are employed. Closer to home, these materials are being researched in order to harness all the waste heat generated by machinery, such as from factories or cars, and then convert them into usable electricity. However, current materials lack high efficiencies and so research in the field has been working to improve that.
My lab has discovered a new family of compounds, CsMxSi1-xAs2 (M = Cu, Zn, Ga), that can be used for thermoelectric purposes. These compounds consist of SiAs2 layers with interlaying Cs atoms. Efficient thermoelectric materials require high electrical conductivity and low thermal conductivity. These characteristics may be achieved due to the presence of the SiAs2 layers and the loosely bound Cs atoms, which can prevent heat from spreading through the material. Cu, Zn, and Ga substitute in the Si position for charge balance and potential tuning of material properties. I am working on the synthesis and optimization of this system, so that property measurements can be performed and evaluated. In addition, my research will contribute to the fundamental knowledge of the structure-property relationship of thermoelectric materials for further development.