Extremely Low Contact Resistivity of Bi2Te3-Based Modules Enabled by NiP-Based Alloy Barrier

Electrode diffusion barrier plays an important role in thermoelectric cooling devices. Compared with p-type Bi0.5Sb1.5Te3, the compatibility between commercial Ni barrier and n-type Bi2Te2.7Se0.3 is a key bottleneck to enhance the performance of Bi2Te3-based cooling devices. This paper proposed a NiP alloy barrier to improve the compatibility with n-type Bi2Te2.7Se0.3, and systemically investigated the contact and interfacial dynamics properties. Due to the low diffusion rate of NiP alloy, the initial interfacial contact resistivity of Bi2Te2.7Se0.3/NiP is as low as 0.90 mu Omega cm(2), and it further can be depressed below 1.98 mu Omega 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 Bi2Te3-based modules.

Automated summary

This paper proposes a NiP alloy barrier to improve the compatibility between n-type Bi2Te2.7Se0.3 and commercial Ni barrier, and systematically investigates the contact and interfacial dynamics properties. The results show that the NiP barrier has better thermal stability and can achieve high temperature difference cooling.