Achieving high thermoelectric quality factor toward high figure of merit in GeTe

Suwardi, Ady; Cao, Jin; Zhao, Yunshan; Wu, Jing; Chien, Sheau Wei; Tan, Xian Yi; Hu, Lei; Wang, X.; Wang, W.; Li, D.; Yin, Yan; Zhou, Wu‐Xing; Repaka, D. V. Maheswar; Chen, J.; Zheng, Yun; Yan, Qingyu; Zhang, G.; Xu, Jianwei

doi:10.1016/j.mtphys.2020.100239

Cited by 69 publications

(45 citation statements)

References 69 publications

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“…As a consequence of native Ge vacancies, most of previous studies utilized the aliovalent dopant on the Ge site to reduce the hole concentration, such as Bi, [ 61,63,64,66 ] Sb, [ 62,73 ] In, [ 74,75 ] and transition metals (Ti, [ 67,68 ] Cr, [ 53 ] Cd, [ 69–71 ] and Cu [ 51,54 ] ). Among them, some dopants also obviously contributed to modifying the structure symmetry from rhombohedral to cubic, represented by means of the increased interaxial angle α.…”

Section: Figurementioning

confidence: 99%

High Power Factor and Enhanced Thermoelectric Performance in Sc and Bi Codoped GeTe: Insights into the Hidden Role of Rhombohedral Distortion Degree

Liu

Gao

Zhang

et al. 2020

Advanced Energy Materials

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Modification of crystal symmetry induced by chemical doping or alloying is well known to optimize the charge carrier transport properties in thermoelectric materials. Historically, the altered defect chemistry of the targeted materials, however, has long been neglected or underestimated, which may, in turn, favorably or adversely affect the thermoelectric properties. Herein, using a case study of thermoelectric GeTe, first, the hidden role of rhombohedral distortion degree on the Ge‐vacancy formation energy is theoretically unraveled, and it is experimentally found that Sc and Bi codoping realize a superior thermoelectric performance. Density functional theory calculations demonstrate that the distorted rhombohedral lattice closer to cubic would unexpectedly induce the significantly decreased formation energy of Ge vacancies, resulting in the spontaneous formation of higher‐concentration Ge vacancies. Sc doping is found to be the most effective dopant to reduce the carrier concentration without obviously affecting the rhombohedral distortion degree, leading to the realization of a record‐high power factor. Benefiting from the suppressed thermal conductivity by further Bi doping, an ultrahigh average ZT ≈1.2 from 300 to 723 K is achieved. These discoveries provide new insights into the relationship between crystal symmetry and defect chemistry, and also promote GeTe materials for future thermoelectric applications.

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Section: Figurementioning

confidence: 99%

High Power Factor and Enhanced Thermoelectric Performance in Sc and Bi Codoped GeTe: Insights into the Hidden Role of Rhombohedral Distortion Degree

Liu

Gao

Zhang

et al. 2020

Advanced Energy Materials

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“…To date, the majority of high-performing thermoelectric materials are chalcogenides, such as SnSe-, GeTe-, PbTe-, PbSe-, and Bi 2 Te 3 -based materials [56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75]. In addition, efforts using both theoretical and experimental and even machine learning approaches are continued to be spent on discovering and improving materials performances [66,[76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92].…”

Section: Thermoelectric Devicesmentioning

confidence: 99%

Potential of Recycled Silicon and Silicon-Based Thermoelectrics for Power Generation

et al. 2022

Self Cite

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Thermoelectrics can convert waste heat to electricity and vice versa. The energy conversion efficiency depends on materials figure of merit, zT, and Carnot efficiency. Due to the higher Carnot efficiency at a higher temperature gradient, high-temperature thermoelectrics are attractive for waste heat recycling. Among high-temperature thermoelectrics, silicon-based compounds are attractive due to the confluence of light weight, high abundance, and low cost. Adding to their attractiveness is the generally defect-tolerant nature of thermoelectrics. This makes them a suitable target application for recycled silicon waste from electronic (e-waste) and solar cell waste. In this review, we summarize the usage of high-temperature thermoelectric generators (TEGs) in applications such as commercial aviation and space voyages. Special emphasis is placed on silicon-based compounds, which include some recent works on recycled silicon and their thermoelectric properties. Besides materials design, device designing considerations to further maximize the energy conversion efficiencies are also discussed. The insights derived from this review can be used to guide sustainable recycling of e-waste into thermoelectrics for power harvesting.

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“…In addition to low dimensional materials, the concept of enhancing the slope of density of states vs the energy has been successfully applied using resonant doping in bulk 3D materials. Most notably, elements Tl and In have been shown to be a resonant dopant for PbTe and GeTe, respectively [ 12 , 55 , 56 ]. These observation suggests that physical intuition derived from the studies of low dimensional materials can also be applied to a bulk materials system.…”

Section: Benefits Of Nanostructuringmentioning

confidence: 99%

Bottom-Up Engineering Strategies for High-Performance Thermoelectric Materials

Zhu

Wang

et al. 2021

Nano-Micro Lett.

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The recent advancements in thermoelectric materials are largely credited to two factors, namely established physical theories and advanced materials engineering methods. The developments in the physical theories have come a long way from the “phonon glass electron crystal” paradigm to the more recent band convergence and nanostructuring, which consequently results in drastic improvement in the thermoelectric figure of merit value. On the other hand, the progresses in materials fabrication methods and processing technologies have enabled the discovery of new physical mechanisms, hence further facilitating the emergence of high-performance thermoelectric materials. In recent years, many comprehensive review articles are focused on various aspects of thermoelectrics ranging from thermoelectric materials, physical mechanisms and materials process techniques in particular with emphasis on solid state reactions. While bottom-up approaches to obtain thermoelectric materials have widely been employed in thermoelectrics, comprehensive reviews on summarizing such methods are still rare. In this review, we will outline a variety of bottom-up strategies for preparing high-performance thermoelectric materials. In addition, state-of-art, challenges and future opportunities in this domain will be commented.

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Achieving high thermoelectric quality factor toward high figure of merit in GeTe

Cited by 69 publications

References 69 publications

High Power Factor and Enhanced Thermoelectric Performance in Sc and Bi Codoped GeTe: Insights into the Hidden Role of Rhombohedral Distortion Degree

High Power Factor and Enhanced Thermoelectric Performance in Sc and Bi Codoped GeTe: Insights into the Hidden Role of Rhombohedral Distortion Degree

Potential of Recycled Silicon and Silicon-Based Thermoelectrics for Power Generation

Bottom-Up Engineering Strategies for High-Performance Thermoelectric Materials

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