Titanium-based thin film metallic glass as diffusion barrier layer for PbTe-based thermoelectric modules

Abstract

The thin film metallic glass (TFMG) is an effective diffusion barrier layer for PbTe-based thermoelectric (TE) modules. Reaction couples structured with Cu/TFMG/PbTe are prepared via sputter-deposition and are annealed at 673 K for 8-96 h. The transmission line method is adopted for the assessment of electrical contact resistivity upon the PbTe/TFMG, and the value remains in the range of 3.3-2.5 × 10−9 (Ω m2). The titanium-based TFMG remains amorphous upon annealing at 673 K for 48 h and effectively blocks the inter-diffusion by not having grain-boundaries, which only allows the bulk diffusion between the metal electrode and the TE substrate.

Screening Metal Electrodes for Thermoelectric PbTe

“…Surprisingly, the results in this work indicate that the Co element enables even better electrical contact for the PbTe device. Actually, the interfacial contact resistivity of the Co/PbTe joint in this work is the lowest among the electrodes reported in PbTe. ,,− Therefore, it is reasonable to conclude that Co can be considered the top candidate electrode for PbTe.…”

“…Thus, a diffusion barrier layer inertial to PbTe, such as Fe , and Co alloys, ,, is usually required when choosing the above-mentioned metals as electrodes. Although this kind of multiple-layer electrode structure is widely used in many thermoelectric devices, , the complicated structure increases the difficulty of device fabrication. This motivates this work, in a high-throughput way, focusing on seeking good electrodes that can be directly bonded to PbTe with low interfacial resistance.…”

Challenges and Progress in Contact Development for PbTe‐based Thermoelectrics

“…Thin film contact layers of Ti and Ti-based (Ti 45.8 Zr 9.5 Cu 29.5 Nb 8.6 Co 6.6 ) thin film metallic glass (TFMG) deposited by radio frequency (RF) magnetron sputtering on a PbTe substrate had 1 c ~570 × 10 À 10 Ω m 2 (~1790 × 10 À 10 Ω m 2 after 30 min annealing at 673 K) and 1 c ~33 × 10 À 10 Ω m 2 (2 5 × 10 À 10 Ω m 2 after 30 min annealing at 673 K), respectively. [41] While PbÀ TeÀ Ti intermetallic compounds were formed at the Ti/PbTe interfaces at 673 K, no significant chemical interaction was observed within the initial ~24-48 h of annealing at 673 K at the interface of the Ti-based TFMG with PbTe. [41] This has been attributed to the amorphous character of the TFMG blocking diffusion due to the lack of grain boundaries.…”

“…[17,37] These are the primary selection criteria for thermoelectric materials in general. [24,25] For the development of PbTe-based thermoelectric modules, various metals, alloys, and compounds have been tested as contact materials, including Al, [38][39][40] Ti, [41] Fe, [19][20][21][22][23]29,31,38,[42][43][44][45][46][47][48][49][50][51][52][53] Co, [48,[54][55][56][57] Co 80 Fe 20 , [14,17,31,[58][59][60][61] Ni, [29,38,48,49,51,54,56,57,[62][63]…”

Methods for investigation of electrical contact resistance in a metal film--semiconductor structure

“…Low values of contact resistance in semiconductormetal contact structure significantly complicate its experimental determination. The method of contact resistance measurement similar to well-known method of TLM (Transmission line method) [8,[15][16][17][18] is proposed in this study.…”