Preparation and Characterization of Ni/Bi0.5Sb1.5Te3 Heterogeneous Multilayered Thermoelectric Materials

Abstract

It is difficult to achieve coordinated optimization in thermoelectric materials due to the strong coupling between the electrical and thermal transport properties. However, interface effects, especially those caused by heterogeneous interfaces, are promising to overcome this challenge. In this work, the Ni/Bi 0.5 Sb 1.5 Te 3 (BST) heterogeneous multilayer structure thermoelectric materials were fabricated by the combination of vacuum evaporation deposition and spark plasma sintering. The influence of Ni layer on the phase composition, microstructure and thermoelectric performance along the different directions (0°, 30°, 60°and 90°, the angles between the performance measurement direction and the Ni layer) of Ni/BST materials were systematically investigated. The microstructural analysis indicates that the distinct heterogeneous interfaces were firmly bonded, and the interface reaction layer was composed of Ni and Te. As compared with the matrix, the electrical conductivity and Seebeck coefficient of the Ni/BST heterogeneous multilayer thermoelectric materials increased, and the thermal conductivity slightly reduced. For Ni/BST90°sample, the maximum ZT value of 1.05 was achieved at 370 K, increased by 19.1% compared with the BST90°. Our work demonstrates that the electron and phonon transport properties can be simultaneously optimized by introducing the ordered heterogeneous interfaces.

Excellent Thermoelectric Performance from In Situ Reaction between Co Nanoparticles and BiSbTe Flexible Films

“…The effective mass remains the same because the Co-NPs have little effect on the band structure of the Bi 0.5 Sb 1.5 Te 3 matrix. 22,24 After the introduction of Co-NPs, the carrier concentration increases, resulting in an overall decrease in the Seebeck coefficient (Figure 6b). It is worth noting that the Seebeck coefficient can be largely preserved with optimized Co-NPs concentrations.…”

Thermal Treatment Effects on the Thermoelectric Properties of Ni/Si/Si + Sb/Si/Si + Ge/Ni Multilayer Thin Films

“…These multilayer thin film systems have shown remarkable high Seebeck coefficient values due to the selection of different material systems and using Ni thin films for removing of an excess of heat during the operation of the thermoelectric device. The high Seebeck coefficient might come from due to the interfacal reaction between Ni and other deposited multilayer thin films (Guo et al, 2019). Figure 3 shows the thermal treatment dependence of the Seebeck coefficients for Ni/200 layers of Si/Si + Sb/200 layers of Si/Si + Ge/Ni thin films.…”

“…The current material systems reached remarkable Seebeck coefficient at the suitable annealing temperatures and the operation temperatures. Ni layers used for both at the top and bottom of the fabricated devicess could cause removing of heat from the thermoelectric devices during operation and the high Seebeck coefficient might come from due to the interfacial reaction between Ni and other deposited multilayer thin films (Guo et al, 2019). For the future works, the thickness of Ni and annealing temperatures could be changed and results could be compared to each other.…”

Boosting Thermoelectric Performance of Bi2Te3 Material by Microstructure Engineering

“…In Figure 1a, the as-deposited Bi 2 Te 3 /Sb thin film show diffraction peaks corresponding to rhombohedral Bi 2 Te 3 (JCPDS NO. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. This indicates the formation of nano crystallites of Bi 2 Te 3 in the thin film at room temperature.…”

“…Besides, multilayer TE thin films have been developing in the past. Guo et al fabricated Ni/Bi 0.5 Sb 1.5 Te 3 TE material with multilayer structure, which exhibits the PF greater than 4 mWm −1 K −2 at 300 K. [16] Liao et al measured TE properties of spurted Sb/Bi-Sb-Te multilayer thin films after electrical stress. The PF of 1.36 mWm −1 K −2 was achieved at 603 K. [17] Kim et al deposited Sb 2 Te 3 /Bi 2 Te 3 multilayer films via magnetron sputtering system, whose PF reached 493 μWm −1 K −2 at room temperature.…”