A Facile Synthesis Method of BiSb Nanoparticles for Thermoelectric Applications
- PDF / 1,052,213 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 49 Downloads / 223 Views
ORIGINAL PAPER
A Facile Synthesis Method of BiSb Nanoparticles for Thermoelectric Applications V. Asvini 1
&
G. Saravanan 1 & R. K. Kalaiezhily 1 & M. Pavithra 1 & K. Ravichandran 1
Received: 10 July 2020 / Accepted: 29 October 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract BiSb nanoparticles were synthesized by solvothermal method. The synthesized material having a trigonal structure with space group R3m was confirmed through X-ray diffraction pattern. The Williamson-Hall method was employed to analyze the lattice stress and micro-strain produced in the BiSb nanoparticles. On the prepared material surface morphology studies were carried out using HR-SEM with EDXA. UV-visible absorption spectrum shows a wide absorption peak at 287 nm and the estimated band gap value is at Eg = 1.6 eV (from Tauc plot). The values of remanent polarization Pr = 0.156 μC/cm2, saturation polarization Ps = 0.253 μC/cm2, and coercive electric field Ec = 13.5 kV/cm obtained from the loop were close to the value. The BiSb nanoparticles exhibit semi-metallic-reported characteristics. This material is useful for thermoelectric power generation applications. Keywords Solvothermal . Micro-strain . Polarization . Semiconducting . Thermoelectric
1 Introduction Thermoelectric materials draw interest due to their characteristic properties, i.e., their unusual transport property and for their potential for technological applications [1]. Having the atomic radii of close values, crystalline structures, and electronic configurations of same type, Bi and Sb semimetals form a continuous series of solutions whose band structure varies with the change in composition of semimetals. So far, a study was done on the thermoelectric materials involving the semiconducting alloy system of BiSb. Elemental bismuth and antimony are both semimetals, and form a continuous solid solution for all compositions. For an intermediate composition, due to the effects of crossing of band, semiconducting rather than semi-metallic behavior is observed: a band gap likely to originate for the compositions of 7% Sb grows to a maximum value at about 17% Sb content and then terminate at about 22% Sb content where the alloy becomes semi-metallic again all the way to pure Sb [2–4]. For the BiSb n-type thermoelectric alloy to be utilized in a low temperature cooling applications, an artificially, mechanically, and thermally perfect p* K. Ravichandran [email protected] 1
Department of Nuclear Physics, University of Madras, Chennai, Tamil Nadu 600 025, India
type thermoelectric alloy must be produced [5–7]. P-Type BiSb alloys obtained through Sn doping have been described previously [2, 8]. However, it implies that the system must be recognized as a strongly degenerate semiconductor. The employment of polycrystalline materials would be more appropriate for such applications. But the problem with the usage of polycrystalline BiSb alloy is its lower figure of merit (Z) value. To improve Z value, various synthesis methods have been adopted, such
Data Loading...
