Enhancement of bonding strength in BiTe-based thermoelectric modules by electroless nickel, electroless palladium, and immersion gold surface modification

Nguyen, Yen Ngoc; Kim, Subin; Bae, Sung Hwa; Son, Injoon

doi:10.1016/j.apsusc.2021.149005

Cited by 18 publications

(8 citation statements)

References 31 publications

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“…For this work, Ti (α avg = 8.6 × 10 −6 K −1 ) and Nb (α a = 7.3 × 10 −6 K −1 ) were selected to realize contacts on CrSi 2 because they showed a relatively similar thermal expansion behavior [35]. Several different contact fabrication processes were reported in the literature for thermoelectrics such as sputtering [36], electroless plating [37], or thermalspraying [38]. In the present work, the process simply consisted in placing the CrSi 2 powder between two layers of metallic powder in the same graphite die and to densifying the whole together by SPS sintering.…”

Section: Fabrication Of Ti and Nb Electric Contacts On Crsimentioning

confidence: 99%

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

et al. 2021

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CrSi2 is a promising thermoelectric material constituted of non-toxic and earth abundant elements that offer good perspectives for the mass production of inexpensive and reliable thermoelectric modules for waste heat recovery. Realization of robust metallic contacts with low electrical and thermal resistances on thermoelectric materials is crucial to maximize the conversion efficiency of such a device. In this article, the metallization of an undoped CrSi2 with Ti and Nb using a conventional Spark Plasma Sintering process is explored and discussed. These contact metals were selected because they have compatible thermal expansion coefficients with those of CrSi2, which were determined in this study by X-ray Diffraction in the temperature range 299–899 K. Ti was found to be a promising contact metal offering both strong adhesion on CrSi2 and negligible electrical contact resistance (<1 μΩ cm2). However, metallization with Nb resulted in the formation of cracks caused by large internal stress inside the sample during the fabrication process and the diffusion of Si in the metallic layer. A maximum conversion efficiency of 0.3% was measured for a sandwiched Ti/CrSi2/Ti thermoelectric leg placed inside a thermal gradient of 427 K. The preliminary results obtained and discussed in this article on a relatively simple case study aim to initiate the development of more reliable and efficient CrSi2 thermoelectric legs with an optimized design.

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Section: Fabrication Of Ti and Nb Electric Contacts On Crsimentioning

confidence: 99%

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

et al. 2021

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“…The results are plotted in Figure d and also listed in Table S2. It can be seen that the Ni/Bi 2 Te 3 joints prepared by plating methods have contact resistance in the range of 5–10 μΩ cm 2 with a bonding strength of ∼8 MPa. ,, The bonding strength of joints prepared by spark plasma sintering (SPS) method could reach 10–20 MPa, but the contact resistance for the n-type joint is too high (210 μΩ cm 2 ). , Moreover, the SPS process is complex and not suitable for large-scale production. The contact resistance of the evaporated Ni/Au double barrier layer is relatively higher, which was 37 μΩ cm 2 .…”

Section: Resultsmentioning

confidence: 99%

“…The most commonly used barrier layer in Bi 2 Te 3 -based TE devices is Ni metal. Ni has several advantages including good electrical conductivity and thermal conductivity, good wettability to the Sn-based solder, small CTE difference to Bi 2 Te 3 , good blocking effect, and low cost and high efficiency in preparation. − As a barrier layer, Ni not only provides a strong interfacial bonding strength with TE legs but also forms Ni/Bi 2 Te 3 joints with low interfacial contact resistance. However, since Ni is prone to reaction with Te at high temperature, the devices become very unstable, which leads to significant performance deterioration and even device failure.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Contact Performance and Thermal Tolerance of Ni/Bi₂Te₃ Joints for Bi₂Te₃-Based Thermoelectric Devices

Zhang

Wei

Zhang

et al. 2023

ACS Appl. Mater. Interfaces

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Ni metal has been widely used as a barrier layer in Bi2Te3-based thermoelectric devices, which establishes stable joints to link Bi2Te3-based legs and electrodes. However, the Ni/Bi2Te3 joints become very fragile when the devices were exposed to high temperature, causing severe performance deterioration and even device failure. Herein, stable Ni/Bi2Te3 joints have been established by arc spraying of the Ni barrier layer on the Bi2Te3-based alloys. The interface microstructure and contact performance including the bonding strength and contact resistivity of the arc-sprayed Ni/Bi2Te3 joints are investigated. The results indicate that, as compared with traditional Ni/Bi2Te3 joints, the arc-sprayed Ni/Bi2Te3 joints have comparably low contact resistivity while possessing a 50% higher bonding strength. Aging the joints as an exposure to high-temperature circumstances, the arc-sprayed Ni/Bi2Te3 joints exhibit much better tolerance to the thermal shock with stable bonding strength and contact resistivity. The enhanced interfacial contact performance and thermal tolerance should be attributed to the thick Ni barrier layer and interface reaction layer with good Ohmic contact. This work provides an effective strategy to establish stable joints for the Bi2Te3-based thermoelectric devices with improved thermal stability.

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“…This can be accompanied by the formation of solid solutions or intermetallic compounds at contact interface, which have a lower value of electrical conductivity and mechanical strength. Therefore, in a number of cases, it is necessary to organize a diffusion barrier between the substrate and the deposited contact layer [6,11,13,14,[30][31][32].…”

Section: Factors Determining the Adhesive Strength Of Film Coatingsmentioning

confidence: 99%

XVII Interstate Conference Thermoelectrics and Their Applications --- 2021" (ISCTA 2021 St. Petersburg, September 13-16, 2021 Obtaining and investigation of ohmic contacts with high adhesion to thermoelements

et al. 2022

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The factors determining the adhesive strength of film coatings are considered. The functions of contacts in thermoelements used in a wide temperature range were determined. It was established that the adhesive strength of contact is a limiting factor in the mechanical strength of a thermoelement. A method of vacuum sputtering of thin-film contacts was proposed, including the surface treatment of samples of thermoelectric materials. The presence of a transition layer in the area of the metal-thermoelectric material contact, formed during the interaction of the metal with elements of the thermoelectric material, was established. The dependence of the adhesive strength of film contact on roughness of surface on which they formed was established. Thermal stable contacts for thermoelements with low resistivity of the order of 10-9 Ω·m2 and high adhesion strength of at least 12 MPa were obtained by ion-plasma sputtering. Keywords: thermoelements, contacts, thin films, adhesion, contact resistance.

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Enhancement of bonding strength in BiTe-based thermoelectric modules by electroless nickel, electroless palladium, and immersion gold surface modification

Cited by 18 publications

References 31 publications

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

Enhanced Contact Performance and Thermal Tolerance of Ni/Bi₂Te₃ Joints for Bi₂Te₃-Based Thermoelectric Devices

XVII Interstate Conference Thermoelectrics and Their Applications --- 2021" (ISCTA 2021 St. Petersburg, September 13-16, 2021 Obtaining and investigation of ohmic contacts with high adhesion to thermoelements

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Enhancement of bonding strength in BiTe-based thermoelectric modules by electroless nickel, electroless palladium, and immersion gold surface modification

Cited by 18 publications

References 31 publications

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

Fabrication and Evaluation of Low-Cost CrSi2 Thermoelectric Legs

Enhanced Contact Performance and Thermal Tolerance of Ni/Bi2Te3 Joints for Bi2Te3-Based Thermoelectric Devices

XVII Interstate Conference Thermoelectrics and Their Applications --- 2021&quot; (ISCTA 2021 St. Petersburg, September 13-16, 2021 Obtaining and investigation of ohmic contacts with high adhesion to thermoelements

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Product

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Enhanced Contact Performance and Thermal Tolerance of Ni/Bi₂Te₃ Joints for Bi₂Te₃-Based Thermoelectric Devices

XVII Interstate Conference Thermoelectrics and Their Applications --- 2021" (ISCTA 2021 St. Petersburg, September 13-16, 2021 Obtaining and investigation of ohmic contacts with high adhesion to thermoelements