Superflexible Inorganic Ag₂Te_0.6S_0.4 Fiber with High Thermoelectric Performance

Abstract

Fiber‐based inorganic thermoelectric (TE) devices, owing to the small size, light‐weight, flexibility, and high TE performance, are promising for applications in flexible thermoelectrics. Unfortunately, current inorganic TE fibers are strictly constrained by limited mechanical freedom because of the undesirable tensile strain, typically limited to a value of 1.5%, posing a strong obstacle for further application in large‐scale wearable systems. Here, a superflexible Ag2Te0.6S0.4 inorganic TE fiber is demonstrated that provides a record tensile strain of 21.2%, such that it enables various complex deformations. Importantly, the TE performance of the fiber shows high stability after ≈1000 cycles of bending and releasing processes with a small bending radius of 5 mm. This allows for the integration of the inorganic TE fiber into 3D wearable fabric, yielding a normalized power density of 0.4 µW m−1 K−2 under the temperature difference of 20 K, which is approaching the high‐performance Bi2Te3‐based inorganic TE fabric and is nearly two orders of magnitude higher than the organic TE fabrics. These results highlight that the inorganic TE fiber with both superior shape‐conformable ability and high TE performance may find potential applications in wearable electronics.

Photothermoelectric Synergistic Hydrovoltaic Effect: A Flexible Photothermoelectric Yarn Panel for Multiple Renewable-Energy Harvesting

“…In Figure g, by comparing and analyzing the results of this study with those of other similar works and photothermal electrical components, we find that the work of this study is competitive. There is still a lot of unexplored potential in the field of photothermal electrical devices, and this work contributes positively to the development of this field and provides certain reference values for future research. ,,,,,− …”

Advances in flexible inorganic thermoelectrics

“…In flexible all-inorganic devices based on such Ag 2 S-based materials, the high electrical mobility results in a normalized maximum ω out of up to 0.08 W m −1 at a ΔT close to 20 K. Therefore, rational adjustment of the ratios of S, Se, and Te can achieve materials with both reasonable flexibility and thermoelectric performance to meet specific devices. 43,45,137,[142][143][144][145][146][147][148][149] Besides, some materials with unique composition, such as Ag 20 S 7 Te 3 , also exhibit ductile and promising ZT of 0.8 at 600 K. 150 Based on the compositional design of Ag 2 S 1−x−y Se x-Te y , in addition to conventional doping to further improve their thermoelectric performance, 151 substituting Cu on Ag sites can further tune the thermoelectric performance and flexibility. 107,152 This is because Cubased chalcogenides such as Cu 2 S 153 and Cu 2 Se 22 have demonstrated their high ZTs of >2 at high temperatures, and they are usually p-type semiconductors.…”

“…Given the rapid development in the field of flexible inorganic thermoelectrics, this article comprehensively overviews the advances with a focus on the optimization of their structures and performance. Here, we encompass an overview and synthesis of the preparation methods and practical application areas of inorganic flexible thermoelectric materials and their devices, including Bi 2 Te 3−x Se x , 41 Bi 2−x Sb x Te 3 , 42 Ag 2 X (X = S, Se, Te), [43][44][45] SnX (X = S, Se, Te), 46 InSe, 47 Cu 2 Se, 48 TiS 2 , 49 CoSb 3 , 50 oxides, 51,52 and complex chalcogenides, 53 as illustrated in Figure 1. Furthermore, this review also addresses the challenges currently faced in terms of performance optimization and fabrication processes of flexible inorganic thermoelectric materials.…”

Flexible Ag–S–Te System with Promising Room-Temperature Thermoelectric Performance

“…Subsequently, the flexibility of single-crystal ZnS in the complete darkness and single-crystal InSe is revealed. The relatively large bandgap (∼1 eV) of Ag 2 S gives electrical conductivity on the order of 10 –1 S m –1 , resulting in poor TE performance. , Alloying a certain amount of Se − or Cu , to Ag 2 S is an effective way to improve its TE performance at ambient temperature, and the discovery of amorphous Ag 2 S 0.4 Te 0.6 provides another new idea for optimizing the deformability and TE performance of ductile inorganic semiconductor. − …”