Advanced science: the core-shell structure introduced by in-situ reaction significantly improves the thermoelectric properties of SNTE based materials

thermoelectric materials can realize the mutual conversion of heat energy electric energy simply by establishing temperature difference or applying current which has a very important application prospect in thermoelectric power generation semiconductor refrigeration. The conversion efficiency of thermoelectric materials is mainly controlled by the dimensionless thermoelectric merit ZT ZT = σ s2t / (κ e κ L) where σ s κ E κ L are the electrical conductivity Seebeck coefficient electronic thermal conductivity lattice thermal conductivity of the materials Z is the quality factor t is the corresponding absolute temperature. Because the Seebeck coefficient s the electronic thermal conductivity K E the electrical conductivity σ are related to each other it is not easy to improve the thermoelectric merit of the materials. It is necessary to decouple these parameters to improve the thermoelectric properties of the materials. At present

medium temperature thermoelectric materials mainly include PbTe filled skutterudite. However Pb is harmful to the environment while CO is a rare metal. Therefore it is of great significance to study develop new environmental friendly inexpensive medium temperature thermoelectric materials. SNTE a group of Ⅳ - Ⅵ compound semiconductors has the same crystal structure similar energy b structure as PbTe which is expected to be an important substitute for PbTe. However intrinsic SNTE has very high hole concentration (1020-1021 cm-3) high thermal conductivity large energy splitting between heavy valence b light valence b so the thermoelectric performance of intrinsic SNTE is low needs to be optimized.

Based on this the two-phase β - zn4s composites will be formed by the chemical reaction between tekd zn4s Sb@ZnTe This structure can significantly scatter phonons reduce the lattice thermal conductivity of the system And Sn can not only compensate the SN vacancy in the system reduce the carrier concentration but also adjust the energy b structure of the system so as to effectively improve the electrical properties of the material. Finally the coordinated control of the thermal electrical transport properties of SNTE based materials is realized the maximum thermoelectric merit ZT is 1.32 which is doubled compared with the matrix SNTE. Related work was published in advanced science（ DOI:10.1002/advs.201903493 ）It's on. This work innovatively designed in-situ chemical reaction formed special core-shell microstructure through in-situ reaction coordinated the thermoelectric properties of SNTE materials. The related research ideas are expected to provide important reference for the research development of other thermoelectric materials.

TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years' experience in providing super high-quality chemicals and Nanomaterials. Our company has successfully developed a series of powder materials (including oxides, carbides, nitrides, single metal, etc.), high-purity targets, functional ceramics, and structural devices. OEM service is available. Please contact us if necessary.