Study on the contact resistance of various metals (Au, Ti, and Sb) on Bi–Te and Sb–Te thermoelectric films

Abstract

In this study, we explore various electrode materials (Au, Ti, and Sb) for use as contact materials on Bi2Te3 and Sb2Te3 thermoelectric films. Using the transmission line method (TLM), we measured the specific resistivity of the contacts, which showed that Au has the lowest contact resistivity for both the thermoelectric films (after annealing): 2.7 × 10−10 Ω m2 for Bi2Te3 and 2.9 × 10−11 Ω m2 for Sb2Te3. The specific contact resistivity data suggest that the dominant factor for the contact properties is interface states. After annealing, the contact resistivity does not change much for the Bi2Te3 contacts while it drops greatly for the Sb2Te3 ones. Analysis of the carrier transport mechanism across the contacts discloses that changes in the carrier concentration in the thermoelectric films after annealing are responsible for the different behaviors.

Controllable Electrical Contact Resistance between Cu and Oriented-Bi2Te3 Film via Interface Tuning

“…The SEM images of the Bi 2 Te 3 –Cu multilayer films are shown in Figure . The interfaces are tough in all our samples due to the different oriented microstructures of our Bi 2 Te 3 films (e.g., R a ), which indicates the possibility of the influence of surface states on the contact resistance . Additionally, it can be observed that many defects such as pores generate at the interface between the two layers of Sample 1 (Figure a–c), which may block the transport of electrons and thus result in a large contact resistance.…”

“…Figure is the total resistance plotted as a function of pad spacing for contacts between different oriented Bi 2 Te 3 and Cu measured by TLM, where the contact area is designed as 0.12 mm 2 (<0.4 mm 2 ). The well-fitted lines show the reliability of the TLM model . Extracted R c and ρ c are listed in the table below Figure .…”

“…Commonly, the barrier heights of M–S systems are determined by both work functions and interface states. , When the metal surface is in intimate contact with a semiconductor, a Schottky barrier or an antibarrier layer is formed due to the work function differences, and the latter is usually characteristic of an ohmic contact . For the contacts between Bi 2 Te 3 and metals, the barrier height (Φ B ) of the interfaces is estimated to be within 0.1 eV, and ohmic contact characteristics have been observed in contacts between Bi 2 Te 3 and many metals, for example, Ni, Co, Au, Ti, and Cu. ,, This indicates that the small Φ B formed at the interface of Bi 2 Te 3 –metals will not obstruct the current flow. Thus, the Bi 2 Te 3 –Cu contacts have little dependence on work function.…”

Amorphous InGaZnO and metal oxide semiconductor devices: an overview and current status

“…Finally, as the field of thin-film electronics moves towards flexible applications, the use of ITO is limited as it fails quickly under strain 61,63 . The choice of electrode material, therefore, is highly dependent on the specific application, with TCOs (still predominantly ITO) continuing in established FPD manufacturing, while new alternatives such as carbon nanotubes, graphene, and metallic grids stand to replace ITO when optical transparency is still required but cost and/or flexibility become concerns 41,61,[64][65][66][67] , while simple metal films (or bi-and tri-layer stacks of metals) can be used where transparency is unnecessary and material and processing costs are dominant [68][69][70] , discussed further in section 3.2.4.…”

Metallization and Diffusion Bonding of CoSb3-Based Thermoelectric Materials

“…Yb0.3Co4Sb12 [14] Mo-Ti 9 Bi2Te3 [27] Au 2.73 Mg2Si [28] Ni 210 Hf0.5Zr0.5CoSn0.2Sb0.8 [29] Ag 38 (Mm,Sm)yCo4Sb12 [26] Fe-Ni 2 n-type skutterudite [30] CoSi2 0.4 This work…”