Extremely Low Contact Resistivity of Bi<sub>2</sub>Te<sub>3</sub>-Based Modules Enabled by NiP-Based Alloy Barrier
Erbiao Min, Yifeng Ling, Linghao Zhao, Ying Xu, Li‐Yin Gao, Juan Li, Jianghe Feng, Ping Zhang, Ruiheng Liu, Rong Sun
Abstract
Electrode diffusion barrier plays an important role in thermoelectric cooling devices. Compared with p-type Bi 0.5 Sb 1.5 Te 3, the compatibility between commercial Ni barrier and n-type Bi 2 Te 2.7 Se 0.3 is a key bottleneck to enhance the performance of Bi 2 Te 3 -based cooling devices. This paper proposed a NiP alloy barrier to improve the compatibility with n-type Bi 2 Te 2.7 Se 0.3, and systemically investigated the contact and interfacial dynamics properties. Due to the low diffusion rate of NiP alloy, the initial interfacial contact resistivity of Bi 2 Te 2.7 Se 0.3 /NiP is as low as 0.90 μΩ cm 2, and it further can be depressed below 1.98 μΩ cm 2 even after aging at 423 K for 35 days, indicating the superior thermal stability of the NiP barrier layer compared to the commercial Ni barrier layer. Based on the NiP barrier, a 15-pair bismuth telluride device is prepared and a high cooling temperature difference of 71.5 K at a hot-side temperature of 304 K is achieved, which proves the practical applications potential of NiP barrier for Bi 2 Te 3 -based modules.