Days ago, Professor He Jiaqing in the University’s Department of Physics, in the capacity of correspondent journalist, has published latest result made by his research team in the field of thermoelectric materials in Materials Today (IF: 14.107), Energy & Environmental Science (IF: 20.523) and Advanced Energy Materials (IF: 16.146).
Thermoelectric materials are new-energy materials that can realize conversions between thermal energy and electricity, which have great potential of extensive applications in thermoelectric refrigeration and cogeneration, thus playing an important role in improving the existing rate of energy use and alleviating the energy crisis. However, the large-scale commercial use of thermoelectric materials faces the bottleneck of high cost and low efficiency. As a result, researchers are more and more considering developing and using thermoelectric materials featuring abundant raw materials supply, affordable price and low toxicity.
What Professor He’s research team publishes in Materials Today is a thesis entitled Low-cost, Abundant Binary Sulfides as Promising Thermoelectric Materials, which discusses about the binary sulfides as thermoelectric materials. At first, the thesis introduces the research status of sulfides thermoelectric materials and elaborates on natural advantages of the elements from the perspectives of its abundance in the earth crust, toxicity and price. In terms of the thermoelectric performance, it analyzes the disadvantages of sulfides in thermal stability of sulfides and adjustability of the density of charge carriers. It also proposes methods of optimizing sulfides as thermoelectric materials including the element doping and control of micro-structures. In the end, it points out the potential research orientation of sulfides and possible new methods for the new performance of sulfides as the thermoelectric materials.
The thesis Synergistically Optimized Electrical and Thermal Transport Properties of SnTe via Alloying High-solubility MnTe published in Energy & Environmental Science tells the new progress made by Professor He’s research team in the lead-free thermoelectric materials called SnTe. Based on relevant theoretical calculations and structural characteristics of transmission electron microscope, the thesis reveals how MnTe doping adjusts the band structure and microstructure of SnTe, thus realizing synchronized optimization of power factor and lattice thermal conductivity, and considerably improving the thermoelectric optimal value and conversion efficiency.
The thesis published in Advanced Energy Materials is entitled Tuning Multiscale Microstructures to Enhance Thermoelectric Performance of n-Type Bismuth-Telluride-Based Solid Solutions. The thesis uses various electron microscope technologies to provide evidence that proves the point defects at atomic scale in Bi2Te3 materials, the phase interfaces at nano-meter scale, and all-scale layer structure of crystal and phase interface. At the same time, it uses the theoretical model to discuss the effective diffusion of the full-scale structure on the full spectrum phonon, thus providing reasonable explanations for the super-low lattice thermal conductivity measured in the experiment.
Since working in SUSTC in 2013, Professor He Jiaqing has made a few outstanding progress in the field of thermoelectric materials. The progress is featured by study of the relations between structure and performance of thermoelectric materials via electron microscope. The results made by his research team have captured great domestic and international attention. Recently, the Editor-in-Chief Professor John Plummer also gave great praise for the work of the research team.
Links： http://www.sciencedirect.com/science/article/pii/S1369702115003132
http://pubs.rsc.org/en/content/articlelanding/2015/ee/c5ee02423d
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201500411/abstract
