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Information × Registration Number 0220U002025, 0118U002043 , R & D reports Title The influence of size effects on the thermoelectric properties of thin-film nanostructures based on solid solutions of topological insulators of different types popup.stage_title Head Rogacheva Elena, Доктор фізико-математичних наук Registration Date 10-02-2020 Organization The Kharkov state polytechnical university popup.description2 The object of the study: classical and quantum dimensional effects in thin-film nanostructures based on solid solutions of 3D- and crystalline thermoelectric topological insulators and the effect of structure disorder on the manifestation of these effects in TE properties. Goal of the work: to reveal the dimensional effects in thin films of solid solutions (Bi)2(Te1-xSex)3, (Bi1-xSbx)2Te3, (Bi1-xSbx)2Se3, Bi1-xSbx та Pb1-xSnxTe(Se) and peculiarities of their manifestation related to the presence of a topological surface layer and to determine the impact of these effects on thermoelectric properties. Methods of research: X-ray diffractometry; optical and electronic microscopy; measurement of microhardness, thermoelectric, kinetic and thermal properties. The microstructure and crystalline structure of (Bi)2(Te1-xSex)3, (Bi1-xSbx)2(Te)3 and Bi1-хSbx solid solutions were investigated and the phase composition and the dependence of the unit cell parameter on the composition of bulk crystals were established. Polycrystalline samples of (Bi)2(Te1-xSex)3 і (Bi1-xSbx)2(Te)3 solid solutions are produced by cold pressing and the influence of manufacturing technique on their TE properties was determined. Bi1-xTex thin films (x=0.596-0.627) in a wide range of thicknesses d were grown by vacuum evaporation from a single source when varying different technological conditions (substrate temperature, the state of the original crystals of the mixture, etc.). The influence of technological conditions on the conductivity type and TE parameters of the films was established. Galvanomagnetic properties in the interval of T=4.2-300 К are investigated for Bi2Se3 crystals and films produced from them and the absence of weak localization effects is shown. The temperature dependences of the kinetic coefficients (Т=77-300 К) are obtained for p- і n Bi2Te3 films. The nature of the temperature dependences is explained by the presence of donors and/or acceptor defect states. Product Description popup.authors Водоріз Ольга Станіславівна Дорошенко Ганна Миколаївна Мірзоєв Ільгар Гахірович Мартинова Катерина ВІкторівна Меньшикова Світлана Іванівна Ніколаєнко Ганна Олександрівна Нащекіна Ольга Миколаївна Новак Костянтин Валерійович Рогачова Олена Іванівна Храмова Тетяна Іванівна Шелест Тетяна Миколаївна popup.nrat_date 2020-04-02 Close