High-Performance Ag-Modified Bi_0.5Sb_1.5Te₃ Films for the Flexible Thermoelectric Generator

Abstract

Bi–Sb–Te-based semiconductors possess the best room-temperature thermoelectric performance, but are restricted for application in the wearable field because of their inherent brittleness, rigidity, and nonscalable manufacturing techniques. Therefore, how to obtain thermoelectric materials with excellent thermoelectric properties and flexibility through the batch production process is a serious challenge. Here, we report the fabrication of flexible p-type thermoelectric Ag-modified Bi0.5Sb1.5Te3 films on flexible substrates using a facile approach. Their optimized power factors are ∼12.4 and ∼14.0 μW cm–1 K–2 at 300 and 420 K, respectively. These high-power factors mainly originate from the optimized carrier transport of the composite system, through which a high level of electrical conductivity is achieved, whereas a remarkably improved Seebeck coefficient is simultaneously obtained. Bending tests demonstrate the excellent flexibility and mechanical durability of the composite films, and their power factors decrease by only about 10% after bending for 650 cycles with a bending radius of 5 mm. A flexible thermoelectric module is designed and constructed using the optimized composite films and displays a power density of ∼1.4 mW cm–2 at a relatively small ΔT of 60 K. This work demonstrates the potential of inorganic thermoelectric materials to be made on flexible/wearable substrates for energy harvesting and management devices.

Postsynthetic‐Modified PANI/MOF Composites with Tunable Thermoelectric and Photoelectric Properties

“…Intentional insertion of impurity atoms into nanocrystals by cation exchange has been used to modify semiconductor properties [34–36] . Similarly, we think that the synthesis of doped crystalline MOF by heterovalent cation substitution reaction deserves to be explored.…”

“…Intentional insertion of impurity atoms into nanocrystals by cation exchange has been used to modify semiconductor properties. [34][35][36] Similarly,w et hink that the synthesis of doped crystalline MOF by heterovalent cation substitution reaction deservest ob ee xplored. Univalent silver ions are gaining increasinga ttention due to their excellent photosensitivity and conductivity.H ence, we attempted to introduces ilver ions into Co-MOF by SC-SC conversion for adjusting the opticala nd electricalproperties.…”

Recent Developments in Flexible Thermoelectric Devices

“…The data are taken from refs. [7,12,50,52,59,62,64,68,70,76,77,83,[91][92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108] devices. The thermoelectric materials used in the flexible thermoelectric devices are usually prepared by deposition or printing methods.…”

Thermoelectric effect and devices on IVA and VA Xenes

“…272,275 Compared with bulk devices, thin film or lowdimensional based thermoelectric generators (TEG) have several advantages: reduction in the use of costly materials 276 ; a wide range of different designs and possible flexibility 277 ; possible integration for on-chip cooling or energy harvesting, 278 etc. For instance, the electrical resistance only increases less than 5% when the bending radius is ≥5 mm, providing a promising wearable thermoelectric application ( Figure 6A); 279 a stretchable temperature sensor can measure temperature precisely with poor strain sensitivity, critical in soft robotics ( Figure 6B); 280 3D helical thermoelectric coils can be formed without compromising the flexibility of 2D materials ( Figure 6C); 103,281 a planar or large area pn junction version of TEG is more CMOS compatible than π-type bulk topology ( Figure 6D,E). 273,282 TEG requires a specific combination of TE material itself, contact materials, bonding layers, the ceramic heat spreader, etc.…”

“…(A) R / R 0 dependence on bending radius. Inset: photograph of Bi 2 Te 3 ‐based film bending illustrating bending radius, Copyright 2020, American Chemical Society 279 ; (B) the printed temperature‐sensor array was glued on a soft robotic surface as an artificial skin, Copyright 2019, The Royal Society of Chemistry 280 ; (C) schematic illustration of the fabrication process for 3D helical coil thermoelectric modules, Copyright 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science 281 ; thermoelectric generators topologies of (D) π‐type and (E) large area pn junction, Copyright 2018, Elsevier Ltd. All rights reserved 273 …”