The low-energy electronic structure of SnSe single crystal measured by high-resolution angle-resolved photoelectron spectroscopy: the multi-valley peak energy band and the linear dispersion similar to graphene, and on the basis of which we can understand and find the high thermal and electric potential Pudding 'model of value material
Recently, the Chinese Academy of Sciences superconductivity excellence innovation center, the Shanghai Institute of Microsystem and Information Technology Information Functional Materials State Key Laboratory researcher Shen Dawei team and Zhejiang University Department of Physics researcher Zheng Yi task force, the use of ultra-high resolution angle resolution photoelectron energy Spectrum and cryogenic quantum transport measurement of the two complementary technologies for the first time to achieve the current record of keeping the highest thermoelectric value of the thermoelectric material SnSe fine electronic structure characterization and the successful use of 'defect engineering' to achieve the electronic structure of the material and The effective regulation of thermoelectric properties provides the necessary basis for further utilization of energy-band engineering to synthesize and improve high-performance thermoelectric materials.
The study found that the low-energy electronic structure of SnSe combines a unique 'multivalley' band with a linear dispersion similar to graphene, the former can greatly enhance the Seeback coefficient of the material, which results in The effective mass of electrons in the material is reduced and the conductivity of the material is effectively enhanced, and the combined effect of the two makes the thermoelectricity value of the SnSe material greatly enhanced. On the basis of this, the study proposes that the electron can be understood from the microscopic mechanism The search for the "pudding-mold" of high thermoelectric merit materials is the first time that people have understood the thermoelectric properties of SnSe from an electronic structure perspective. In addition, by introducing artificially controlled SnSe2 impurity states and point dislocations, The effective regulation of the carrier concentration in SnSe material on the basis of maintaining the original basic properties opens up a new theoretical direction and technical foundation for the future synthesis and improvement of high performance thermoelectric materials using 'defect engineering'.
Relevant research results published in the "Nature - Communications", Wang Zhen, Department of Physics, Zhejiang University, Shanghai Institute of Microsystem Ph.D. Fan Congcong papers co-author, Shen Dawei, Zheng Yi as the co-author of this study has been a major national scientific instruments Research projects and other funding.
