Effect of Photon Treatment on Structure and Substructure of Bi2Te3 –xSex Thermoelectric Material
| Autor: | S. B. Kushchev, V. Dybov, A. Kostyuchenko, I. A. Safonov, A. A. Grebennikov, D. V. Serikov, E. K. Belonogov, V. A. Yuryev |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Scanning electron microscope General Engineering Analytical chemistry Recrystallization (metallurgy) 02 engineering and technology 021001 nanoscience & nanotechnology Thermoelectric materials 01 natural sciences Nanocrystalline material Transmission electron microscopy Phase (matter) 0103 physical sciences General Materials Science Surface layer 0210 nano-technology Solid solution |
| Zdroj: | Inorganic Materials: Applied Research. 11:338-342 |
| ISSN: | 2075-115X 2075-1133 |
| DOI: | 10.1134/s2075113320020069 |
| Popis: | X-ray diffractometry, scanning electron microscopy and transmission electron microscopy techniques were used to study the phase composition and morphology as well as structure and substructure of semiconductor plates based on Bi2Te3 –xSex before and after photon treatment (PT) by radiation of high-power xenon lamps (spectral range λ = 0.2–1.2 μm) in an Ar atmosphere. It was found that the PT results in recrystallization of the near-surface layers (~2 μm) of the Bi2Te3 – xSex solid solution with the formation of inhomogeneous structure in the form of microcrystals surrounded by nanocrystalline grains. It also changes the chemical composition of the near-surface layer (~5 μm) associated with an increase in the concentration of selenium. More than a 40-fold increase in the area of intergrain boundaries and the formation of nanocontacts along the boundaries of the microcrystalline phase make a significant contribution to the scattering of phonons, and a change in the concentration of tellurium and selenium leads to a decrease in the electronic component of thermal conductivity. Substructural changes correlate with a significant (up to 5%) reduction in the thermal conductivity of samples of Bi2Te3 – xSex solid solution with a surface layer modified as a result of PT. |
| Databáze: | OpenAIRE |
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