Recent Advances of Layered Thermoelectric Materials

Abstract

of electronic and phononic subsystems, the enhancement in a parameter can frequently deteriorate another, making the improvement of ZT very challenging. [2b-d] Based on Peltier and Seebeck effects, thermoelectric materials are widely used in up-to-date thermoelectric refrigeration and power-generation devices. [3] The schematic illustration of typical thermoelectric refrigeration and power-generation modes are shown in Figure 1. As shown in the figure, the thermoelectric module consists of a p-type and an n-type material, which are interconnected by a metallic electrical contact pads. The actual thermoelectric module is composed of an array of these couples, allowing an efficient thermoelectric energy conversion when a temperature gradient is applied. Conversely, when the current is passed through a thermoelectric module, a temperature gradient will be generated due to Peltier effect. [3] The heat could then be absorbed in the cold side and eventually being withdrawn by the sink, and therefore leads to the effect of refrigeration. In order to improve the efficiency, Lim et al. proposed a cascade refrigeration system using the thermoelectric modules. [4] In the cascade system, the heat absorption efficiency is 1.7 times better than the single system, and temperature difference of the thermoelectric module is significantly lowered to 30 °C compared to 60 °C of the single system, which made it possible to apply thermoelectric refrigerators to small capacity household applications. In 2018, a novel wearable thermoelectric generator was designed and fabricated by Kim et al. [5] This application could be easily attached to human skin for utilizing human body heat as the heat source, and thus could be used in various applications, such as self-powered wearable electrocardiography, and self-powered wireless sensor network for industry. This reflects the recent trend for developing thermoelectric technology with strong focuses on portable, flexible household and industry devices.Layered materials have long been investigated as promising thermoelectric materials in the past 50 years, from the early prototypes of PbTe and Bi 2 Te 3 . [2b] With different strengths of interlayer chemical bondings, the layered materials could be divided into two categories: typical covalent/ionic natural bulk layered materials, such as layered cobalt oxides, [7] bismuth oxyselenide, [8] artificial layered materials, such as superlattices including Bi 2 Te 3 /Sb 2 Te 3 , [9] SrTiO 3 /SrTi 0.8 Nb 0.3 O 3 , [10] GaAs/AlAs; and van der Waals layered materials including Te-based alloy, [2b] as well as artificially engineered van der Waals heterostructures like organic intercalated TiS 2 . [11] In the former case, both the intra-and interlayer chemical bondings With the continuous demands on developing renewable energy technologies to solve the global energy crisis, thermoelectric materials have attracted huge attention due to their ability to convert waste heat to useful electricity. The main advantage of layer-structured materials for thermoel...

Thermoelectric properties of W1−xNbxSe2−ySy polycrystalline compounds

“…In this article, we discuss thermoelectric properties of compounds from the family of transition-metal dichalcogenides (TMDCs) with layered structure. [1][2][3][4][5][6][7][8] The single crystals of | 6061 YAKOVLEVA Et AL.…”

“…Therefore, the search for new high‐efficiency materials for thermoelectric generation is very important in this context. In this article, we discuss thermoelectric properties of compounds from the family of transition‐metal dichalcogenides (TMDCs) with layered structure . The single crystals of TMDCs represent fragile, small sheets that are hard to measure and to use .…”

Powering the Hydrogen Economy from Waste Heat: A Review of Heat‐to‐Hydrogen Concepts

“…[30] Owing to their unit cell structure, the optimization of thermoelectric properties can be greatly enhanced over those of other materials. [30] Owing to their unit cell structure, the optimization of thermoelectric properties can be greatly enhanced over those of other materials.…”

“…Another group of materials that can loosen the interdependence between electrical and thermal conductivity are the layerstructured materials. [30] Owing to their unit cell structure, the optimization of thermoelectric properties can be greatly enhanced over those of other materials. Layered cobalt oxides are the one of the important groups in these compounds.…”

Energy Applications of Magnetocaloric Materials

“…This is one reason why researchers are particularly focusing on solid‐state technologies; the most advanced and most commonly applied examples of these are thermoelectrics, which exploit the Seebeck effect . Recent advances along this line include the development of new materials and fabrication methods, the development of flexible modules, and thermoelectric nanogenerators . Thermoelectric technology systems do not have moving parts, operate over different temperature ranges, and the flexibility of the utilized modules enables a broad variety of applications.…”