Spark Plasma Sintered Bulk Nanocomposites of Bi₂Te_2.7Se_0.3 Nanoplates Incorporated Ni Nanoparticles with Enhanced Thermoelectric Performance

Abstract

Bi2Te3-based compounds are important near room temperature thermoelectric materials with commercial applications in thermoelectric modules. However, new routes leading to improved thermoelectric performance are highly desirable. Incorporation of superparamagnetic nanoparticles was recently proposed as a means to promote the thermoelectric properties of materials, but its feasibility has rarely been examined in mainstream thermoelectric materials. In this study, high quality single-crystalline Bi2Te2.7Se0.3 nanoplates and Ni nanoparticles were successfully synthesized by solvothermal and thermal decomposition methods, respectively. Bulk nanocomposites consisting of Bi2Te2.7Se0.3 nanoplates and superparamagnetic Ni nanoparticles were prepared by spark plasma sintering. It was found that incorporation of Ni nanoparticles simultaneously increased the carrier concentration and provided additional scattering centers, which resulted in enlarged electric conductivities and Seebeck coefficients. The greatly improved ZT was achieved due to the increase in power factor. Spark plasma sintered bulk nanocomposites of Bi2Te2.7Se0.3 nanoplates incorporated by 0.4 mol %Ni nanoparticles (in molar ratio) showed a figure-of-merit ZT of 0.66 at 425 K, equivalent to 43% increase when compared to pure Bi2Te2.7Se0.3 nanoplates. The results revealed that incorporation of magnetic nanoparticles could be an effective approach for promoting the thermoelectric performance of conventional semiconductors.

Isotropic Thermoelectric Performance of Layer-Structured n-Type Bi2Te2.7Se0.3 by Cu Doping

“…Further optimization of carrier concentration and additional methods for decreasing lattice thermal conductivity would improve the thermoelectric property obviously. The average zT values obtained in this work are displayed in Figure d, together with other reported n-type Bi 2 Te 3 -based materials. ,− The average zT in both directions in this work approached to 1.0, which is competitive and promising for achieving a high-energy conversion efficiency.…”

(Bi,Sb)2Te3/SiC nanocomposites with enhanced thermoelectric performance: Effect of SiC nanoparticle size and compositional modulation

“…The κ tot was calculated according to κ tot = DC P d using the thermal diffusion coefficient (D) measured by the laser flash method (LFA 457, Netzsch, Germany). The measurement uncertainties for σ, S and D are approximately 5%, and the measurements were conducted along the direction perpendicular to the SPS compression because the TE performance along this direction is always superior to that along the parallel direction for polycrystalline (Bi,Sb) 2 Te 3 , as has been extensively confirmed in previous studies [37][38][39]. The mass density (d) was obtained by the Archimedes method.…”

Practical High-Performance (Bi,Sb)2Te3-Based Thermoelectric Nanocomposites Fabricated by Nanoparticle Mixing and Scrap Recycling

“…Past research has indicated superior TE performance along the direction perpendicular to the SPS compression compared to the parallel direction for Bi 2 Te 3 -based materials. ,, Therefore, the TE properties of the final commercial p -type (Bi,Sb) 2 Te 3 scraps + SiC samples were conducted along the same direction. The results are presented in Figures and .…”