Thin-film metallic glass: an effective diffusion barrier for Se-doped AgSbTe2 thermoelectric modules

Abstract

The thermal stability of joints in thermoelectric (TE) modules, which are degraded during interdiffusion between the TE material and the contacting metal, needs to be addressed in order to utilize TE technology for competitive, sustainable energy applications. Herein, we deposit a 200 nm-thick Zr-based thin-film metallic glass (TFMG), which acts as an effective diffusion barrier layer with low electrical contact resistivity, on a high-zT Se-doped AgSbTe2 substrate. The reaction couples structured with TFMG/TE are annealed at 673 K for 8–360 hours and analyzed by electron microscopy. No observable IMCs (intermetallic compounds) are formed at the TFMG/TE interface, suggesting the effective inhibition of atomic diffusion that may be attributed to the grain-boundary-free structure of TFMG. The minor amount of Se acts as a tracer species, and a homogeneous Se-rich region is found nearing the TFMG/TE interface, which guarantees satisfactory bonding at the joint. The diffusion of Se, which has the smallest atomic volume of all the elements from the TE substrate, is found to follow Fick’s second law. The calculated diffusivity (D) of Se in TFMG falls in the range of D~10−20–10−23(m2/s), which is 106~107 and 1012~1013 times smaller than those of Ni [10−14–10−17(m2/s)] and Cu [10−8–10−11(m2/s)] in Bi2Te3, respectively.

Fabrication, Corrosion, and Mechanical Properties of Magnetron Sputtered Cu–Zr–Al Metallic Glass Thin Film

“…In recent years, the appearance of thin film metallic glasses (TFMGs) has drawn increasing attention, and some systems with various compositions showing great glass-forming ability (GFA) and superior properties have been comprehensively studied [17][18][19][20]. At present, thin film metallic glass has been used in many fields particularly in microelectromechanical and nanoelectromechanical devices [21], biochemical, biomedical applications [22,23], diffusion barrier layer [24], alloy coatings [25,26], and nanoimprint technology [27].…”

Research Progress of Interfacial Design between Thermoelectric Materials and Electrode Materials

“…The performance of a thermoelectric material is evaluated by the dimensionless figure of merit ZT (=σ S 2 T /κ, where σ, S , T , and κ are the conductivity, Seebeck coefficient, absolute temperature, and thermal conductivity, respectively) . Nevertheless, a thermoelectric generator relies not only on its performance efficiency in the high thermoelectric efficiency (ZT) of its n- and p-type thermoelectric couples but also on good contacts with the electrodes. , This means that, in fabricating the thermoelectric elements, it is necessary to reduce the interface contact resistance between thermoelectric materials and the electrode . Further, a high reliability of thermoelectric devices is also required to ensure the long-term stable output of energy conversion efficiency.…”

Wearable and flexible thin film thermoelectric module for multi-scale energy harvesting

“…Wearable electronic devices (e-wearables) are one of the most important among the emerging enduser technologies [1,2]. With e-wearables, real-time and continuous monitoring of daily human physical and biological activities like fitness, heartbeat rate, blood pressure, body temperature, entertainment, navigation and several other features are made possible [3,4]. An ultra-light, flexible and shape conformable skin-interfaced systems is the current research focus to overcome the key challenges in conventional wearables [5,6].…”