On January 10, 2025, the prestigious journal Science published the latest advances achieved by Professor Zhao Lidong’s research group from Beihang University in the field of thermoelectric materials and devices. The study, titled “Quadruple-band synglisis enables high thermoelectric efficiency in earth-abundant tin sulfide crystals,” realizes the quadruple-band synglisis in the earth-abundant, wide-bandgap tin sulfide (SnS) crystals and substantially enhances the thermoelectric efficiency in terms of power generation as well as thermoelectric cooling. This is the 11th article published in Science by Prof. Zhao Lidong’s group since 2015.
Doctoral student Liu Shan is the first author, with postdoctoral researcher Qin Bingchao, Professor Chang Cheng, and Professor Zhao Lidong serving as corresponding authors. Beihang University is the primary affiliation for the study.
Thermoelectric technology offers an alternative solution for the emerging demand of low-carbon and clean-energy technologies by enabling energy generation or fast cooling through the direct conversion between heat and electricity. With the growing urgency of the dual-carbon strategy, developing green technologies that integrate both power generation and cooling functions is becoming increasingly significant in the energy sector. Thermoelectric technology, which offers advantages such as compact size, precise temperature control, high reliability, and rapid response, has extensive applications in critical areas such as deep space exploration, 5G communications, and microelectronics cooling.
The key challenge in advancing thermoelectric technology lies in achieving high energy-conversion efficiency, which is predominantly influenced by the properties of thermoelectric materials, as expressed by the dimensionless figure of merit (ZT) with ZT = (S2σT)/κtot, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κtot is the total thermal conductivity.The inherent conflicts between thermal and electrical transport pose a considerable challenge to enhancing the overall ZT. A longstanding strategy to enhance the ZT maximum involves introducing various types of defects to reduce lattice thermal conductivity. However, this approach can conflict with the goals of broadening the temperature range of ZT or achieving low-power devices. In response, the research team has suggested a strategy of first identifying intrinsic low-thermal-conductivity materials and then enhancingcarrier mobility (Science 367, 2020, 1196-1197; Science 378, 2022, 832-833).
In the research, the authors improved the thermoelectric efficiency in SnS crystals by promoting the convergence of energy and momentum of four valance bands, termed quadruple-band synglisis. They introduced more Sn vacancies to activate quadruple-band synglisis and facilitate carrier transport by inducing SnS2 in selenium (Se)–alloyed SnS, leading to a high dimensionless figure of merit (ZT) of ~1.0 at 300 kelvin and an average ZT of ~1.3 at 300 to 773 kelvin in p-type SnS crystals. They further obtained an experimental efficiency of ~6.5%, and our fabricated cooler demonstrated a maximum cooling temperature difference of ~48.4 kelvin at 353 kelvin. These results lay a robust foundation for earth-abundant SnS-based thermoelectric devices in both power generation and cooling applications.
Collaborators in this work include: Researcher Chang Chao and Dr. Lou Jing’s group from the National Innovation Institute of Defense Technology, Associate Professor Liu Zhongkai’s group from the ShanghaiTech Laboratory for Topological Physic at ShanghaiTech University, and Researcher Gao Xiang’s group from the Center for High Pressure Science and Technology Advanced Research.
This work was supported by the National Science Fund for Distinguished Young Scholars, the Tencent Xplorer Prize, the National Natural Science Foundation of China, the Beijing Natural Science Foundation, the 111 Project, etc.
Link to the original article: https://www.science.org/doi/10.1126/science.ado1133
Editors: Tian Zimo, Lyu Xingyun
