Performance degradation analysis and fabrication guidance of μ-TEG from material to device

Jiang，Yong1; Shen，Limei1,2; Wang，Yupeng1,3; Song，Mengjie4; Chen，Huanxin1

2023-09-15

10.1016/j.enconman.2023.117371

Energy Conversion and Management   Impact Factor & Quartile

0196-8904

1879-2227

Micro thermoelectric generator (μ-TEG) attracts more and more attention due to its small size and high power density. Many two-dimensional thermoelectric materials with high performance have facilitated the development of μ-TEG. However, the performance of μ-TEG fabricated by these great thermoelectric materials is significantly degraded due to size effect, interfacial effects (include contact effect and boundary effect) and structure effect. To accurately assess the performance degradation degree from material to μ-TEG and guide the device fabrication, an experiment-verified mathematical model considering interfacial and size effects is proposed. Firstly, the phonon/electron temperature distribution in thermoelectric leg of μ-TEG is analyzed to investigate the device-level thermoelectric properties of material. Then based on the device-level thermoelectric properties, the actual power generation performance model of μ-TEG is established to conduct the influence analysis of these effects (boundary, size, contact and structure effects) on material and device. Finally, the thermoelectric leg thickness (H) is optimized to realize optimal power generation. The study results reveal that boundary and size effects weaken the device-level thermoelectric properties, and the reduction trend is more obvious when H is smaller, especially when H ≤ 20 μm. The decrease from the material intrinsic figure of merit ((ZT)) to the device figure of merit ((ZT)) is owing to the boundary effect, structure effect and contact effect, and the dominant factor of this decrease changes from structure effect (H＜7 μm)to contact effect (H ≥ 7 μm) as H increases, which points to a main optimization direction for (ZT) for different H. As for contact effect, the electrical contact resistivity (r) has a more significant impact on weakening the performance of μ-TEG than thermal contact resistivity (r), and their optimization goals are explored (r ≤ 5.1 × 10 Ω·m, r ≤ 9.3 × 10 K·m/W). At given electrical and thermal contact resistivity, there exists an optimal H for achieving the optimal power generation (P) and a large range of H for achieving 95%P, and the optimal H increases with increasing electrical and thermal contact resistivity. This study can reduce the processing difficulty and save time and economic costs of μ-TEG fabrication, which can avoid the blind fabrication of μ-TEG.

Device-level thermoelectric properties Interfacial effects Micro thermoelectric generator Performance degradation Size effect

SCI

English

Others

National Natural Science Foundation of China[52176007];Science, Technology and Innovation Commission of Shenzhen Municipality[JCYJ20210324115611030];

Thermodynamics ; Energy & Fuels ; Mechanics

Thermodynamics ; Energy & Fuels ; Mechanics

WOS:001039116000001

PERGAMON-ELSEVIER SCIENCE LTD

ENGINEERING

2-s2.0-85164317004

Scopus

1.School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan,430074,China
2.Shenzhen Huazhong University of Science and Technology Research Institute,Shenzhen,518057,China
3.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
4.Department of Energy and Power Engineering,School of Mechanical Engineering,Beijing Institute of Technology,Beijing,100081,China

Jiang，Yong,Shen，Limei,Wang，Yupeng,et al. Performance degradation analysis and fabrication guidance of μ-TEG from material to device[J]. Energy Conversion and Management,2023,292.

Jiang，Yong,Shen，Limei,Wang，Yupeng,Song，Mengjie,&Chen，Huanxin.(2023).Performance degradation analysis and fabrication guidance of μ-TEG from material to device.Energy Conversion and Management,292.

Jiang，Yong,et al."Performance degradation analysis and fabrication guidance of μ-TEG from material to device".Energy Conversion and Management 292(2023).