Effect of Ga2O3 Nanoparticles Dispersion on Microstructure and Thermoelectric Properties of p-Type BiSbTe Based Alloys

Abstract

In this study, p-type Bi0.5Sb1.5Te3based nanocomposites with addition of different weight percentages of Ga2O3nanoparticles are fabricated by mechanical milling and spark plasma sintering. The fracture surfaces of all Bi0.5Sb1.5Te3nanocomposites exhibited similar grain distribution on the entire fracture surface. The Vickers hardness is improved for the Bi0.5Sb1.5Te3nanocomposites with 6 wt% added Ga2O3due to exhibiting fine microstructure, and dispersion strengthening mechanism. The Seebeck coefficient of Bi0.5Sb1.5Te3nanocomposites are significantly improved owing to the decrease in carrier concentration. The electrical conductivity is decreased rapidly upon the addition of Ga2O3nanoparticle due to increasing carrier scattering at newly formed interfaces. The peak power factor of 3.24 W/mK2is achieved for the base Bi0.5Sb1.5Te3sintered bulk. The Bi0.5Sb1.5Te3nanocomposites show low power factor than base sample due to low electrical conductivity.

Wide range temperature-dependent (80–630 K) study of Hall effect and the Seebeck coefficient of β -Ga2O3 single crystals

“…Interestingly, the recent reports show that introducing a small amount of Ga2O3 as a secondary phase into the In2O3(ZnO)3 and ZnO materials, the thermal conductivity drastically decreases due to enhancement in the scattering of long-wavelength phonons [16,17]. The mechanical hardness and electrical conductivities are also found to be significantly changed by the addition of Ga2O3 in a state of art thermoelectric materials [18,19].…”

Enhancement of Thermoelectric Performance in Bi0.5Sb1.5Te3 Particulate Composites Including Ferroelectric BaTiO3 Nanodots

“…In 1972, Loffe et al proposed for the first time that point defects are generated by solid-solution alloying, and short-term disorder generates strong phonon scattering. Nanosized oxides as secondary particles can scatter phonons and reduce the lattice thermal conductivity. − For example, Kim et al fabricated Ta 2 O 5 and Bi 0.5 Sb 1.5 Te 3 nanocomposites using high-energy ball milling and spark plasma sintering (SPS). The Seebeck coefficient was increased, while the thermal conductivity (κ) decreased upon the addition of nanoparticles due to enhanced carrier scattering.…”