Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: ISynthesis and Thermoelectric Properties of Bi2Se3 Nanostructures | Kadel et al. Nanoscale Res Lett 2011 6 57 http content 6 1 57 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Synthesis and Thermoelectric Properties of Bi2Se3 Nanostructures 1 11 2 2 K Kadel Latha Kumari WZ Li Jian Yu Huang Paula P Provencio Abstract Bismuth selenide Bi2Se3 nanostructures were synthesized via solvothermal method. The crystallinity of the as-synthesized sample has been analyzed by X-ray diffraction which shows the formation of rhombohedral Bi2Se3. Electron microscopy examination indicates that the Bi2Se3 nanoparticles have hexagonal flake-like shape. The effect of the synthesis temperature on the morphology of the Bi2Se3 nanostructures has also been investigated. It is found that the particle size increases with the synthesis temperature. Thermoelectric properties of the Bi2Se3 nanostructures were also measured and the maximum value of dimensionless figure of merit ZT of was obtained at 523 K. Introduction Thermoelectric TE materials are considered as critical components for solid-state power generating and refrigerating devices 1 . However the state-of-the-art bulk thermoelectric material is only 30 efficient as the refrigerating material when compared to the Freonbased conventional refrigerating material 2 . Hence their relatively low energy conversion efficiency limits the practical application of TE material as a power generator and or refrigerator. The most important issue of the thermoelectric research is to increase the efficiency of thermoelectric materials. The efficiency of TE material can be defined by dimensionless thermoelectric figure of merit ZT ZT 2 T where S is Seebeck coefficient Ơ is electrical conductivity K is thermal conductivity and T is absolute temperature at which figure of merit is measured. The quantity S2Ơ is most commonly referred as power factor. Increase in power factor and decrease in thermal conductivity are required for the enhancement of ZT value. .
