High Performance BiSbTe Alloy for Superior Thermoelectric Cooling

Abstract

At present, the weak thermoelectric and mechanical performance of zone‐melting bismuth telluride alloys cannot support the further improvement of cooling and processing performance of semiconductor refrigeration devices. Here, MnO2 is added into high‐strength Bi0.4Sb1.6Te3 prepared by ball milling method to optimize its thermoelectric transport properties. Via in situ reaction, Sb2O3 nano‐precipitates are formed in the matrix, which also leads to the surplus of Te element. As results, the donor‐like effect is suppressed, thereby increasing carrier concentration and power factor. Besides, volatilization of Te‐rich phases during sintering leaves plentiful nanopores, which together with Sb2O3 nano‐precipitates significantly decrease the lattice thermal conductivity. Eventually, the maximum ZT reaches 1.43 at 75 °C for the Bi0.4Sb1.6Te3+0.01MnO2 sample. On this basis, a 31‐pairs module made of the material and commercial n‐type BiTeSe produces large temperature differences (ΔT) of 70.1, 80.8, and 89.4 K at the hot‐side temperature (Th) of 300, 325, and 350 K respectively, which are highly competitive. The maximum coefficient of performance of 8.6 and cooling capacity of 7 W are achieved when Th is set as 325 K. This excellent progress will promote the further development of bismuth telluride refrigeration modules.

Optimized Thermoelectric Cooler Performance by the Structure-Matching Design of Asymmetrical p/n-Type Legs

“…(a,d) Thermal imaging of the cold side at T h = 300 and 315 K when the current is 0, 1, 3, and 5 A respectively, the (b,e) variation of temperature difference with the operational current, (c) schematic diagram of temperature difference test, (f) Δ T max compared with some typical TE modules of T h = 300 K. Literature data from refs , , , and . The commercial module data is sourced from Advanced Thermal Solution, Inc. and Guangdong Fuxin Technology Co., Ltd ().…”

“…Notably, sample 3 displayed peak temperatures of 70 and 74 K at T h of 300 and 315 K, respectively, which is an outstanding record compared to other state-of-the-art Bi 2 Te 3 -based devices (Figure 5f). 12,14,39,40 From Table 1, devices with superior material properties and matching TE structures have improved Z. This indicates that enhancing the optimum Z of the device is a crucial strategy to improve the cooling performance.…”

“…The above results indicate that enhancing the properties of the material can broaden the temperature difference, a conclusion corroborated by a considerable number of publications. 3,12,14 On this basis, we proceeded to optimize the structure of TE legs based on the material TE properties, resulting in a further enhancement of the cooling effect in the prepared sample 3. Under T h = 300 K condition, sample 3 exhibited an additional 2.7 K increment compared to sample 2 when I was set at 4.5 A.…”

“…The material performance is usually measured by the dimensionless parameter ZT , expressed as ZT = α 2 σ T /κ where α is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the absolute temperature. Currently, Bi 2 Te 3 is the only commercially available room-temperature material in TEDs, and researchers have gone to great lengths to try and make that exaltation in performance of Bi 2 Te 3 -based materials happen, including nanostructure construction, carrier concentration adjustment, energy filtering effects, point defect introduction, etc. − By introducing electron transfer potential traps and texturing, Zhu et al developed the Seebeck coefficient of n-type (Bi, Sb) 2 (Te, Se) 3 materials with high electrical conductivity . The thermal conductivity was successfully reduced by constructing multiscale phonon scattering centers.…”

“…Although these works have realized significant improvement in ZT for Bi 2 Te 3 -based materials, the advancement of ZT is ultimately reflected in the achievement of the TEDs. Researchers are therefore turning to the practical application of high-performance materials in devices, processing high-quality materials into devices to achieve breakthroughs in device properties and industrial development. − …”