Free-standing Bi–Sb–Te films derived from thermal annealing of sputter-deposited Sb₂Te₃/Bi₂Te₃multilayer films for thermoelectric applications

Abstract

ARTICLE This journal isWe introduce an easily acceptable method to produce free-standing Bi-Sb-Te films from Sb 2 Te 3 /Bi 2 Te 3 multilayer films based on solid-state reactions. When sputter-deposited Sb 2 Te 3 /Bi 2 Te 3 multilayer films were annealed at 400 °C under a N 2 gas atmosphere, they were transformed into single layers composed of Bi-Sb-Te films. At the same time, they were spontaneously stripped on a large scale from the substrates (1 cm × 1 cm) without chemical etching. As-fabricated free-standing Bi-Sb-Te films were very flexible, with a thickness of about 400 nm. The findings confirmed that the formation of voids and the strong flow rate of ambient gas play important roles in fabricating free-standing Bi-Sb-Te films during the thermal annealing process. The temperature-dependent crystallization behaviors of each Sb 2 Te 3 and Bi 2 Te 3 film were also investigated to understand the mechanism. Moreover, the thermoelectric properties of free-standing Bi-Sb-Te films were examined with different thickness of films. We believe that this method can contribute to the development of low-dimensional nanostructures that can be useful in various applications such as energy conversion, energy storage and wearable electronics. increased from 68.3 µW / K 2 m to 493.0 µW / K 2 m at room temperature. Although we need to optimize the fabrication process for enhancement of thermoelectric properties, this facile method shows potential for development of free-standing films in thermoelectric applications.

Rapid Surface Oxidation of Sb2Te3 as Indication for a Universal Trend in the Chemical Reactivity of Tetradymite Topological Insulators

“…In contrast to both Shockley and Tamm surface states, TSSs are expected to be quite resistant to surface reactions as long as the bulk atomic structure remains intact. However, for surface device applications, detailed knowledge of the stability limits of the surface properties and the behavior of the TSS under ambient conditions is required, especially as preparation techniques of TIs are being extended toward ultrathin freestanding layers, nanocrystals, nanowires and nanotubes, step-edges, or patterning by lithography . Despite multiple attempts to estimate the reactivity of the prototypical TIs, − many open issues remain.…”

Design guidelines for chalcogenide-based flexible thermoelectric materials

“…39 Besides, a flexible TEG is assembled using the optimum hybrid film, which generates a voltage and a maximum power density of 4.9 mV and 1. 27,51 and alumina 52,53 ) using magnetron sputtering and screen printing processes 54,55 . However, the mechanical properties still cannot meet the requirements of flexible devices.…”

Control of crystal growth and thermoelectric properties of sputter-deposited BiTe thin films embedded with alumina nanoparticles

“…The performance of thermoelectric devices is expressed by the dimensionless figure of merit (ZT), ZT = α 2 Tσ/κ, where α, T, σ and κ are the Seebeck coefficient, absolute temperature, electrical conductivity and thermal conductivity, respectively. 1 Thermoelectric materials with various shapes and sizes, such as nanowires, 2,3 thin films, [4][5][6][7][8][9][10] and bulk materials, have been widely studied. [11][12][13][14] When wearable nanotechnology has been fast developed, thin films have been given attention for thermoelectric application due to their low dimension.…”

“…[11][12][13][14] When wearable nanotechnology has been fast developed, thin films have been given attention for thermoelectric application due to their low dimension. 4,7 Thermoelectric thin films have been prepared by various deposition methods such as screen printing, 4 magnetron sputtering, [5][6][7][8] pulsed laser deposition, 9,10 etc. In particular, magnetron sputtering has been mainly used due to its advantages of high deposition rates, facile deposition process, high-purity films, and excellent adhesion of films.…”