Deep defect level engineering: a strategy of optimizing the carrier concentration for high thermoelectric performance

Zhang, Qian; Song, Qichen; Wang, Xinyu; Sun, Jingying; Zhu, Qing; Dahal, Keshab; Lin, Xi; Cao, Feng; Zhou, Jiawei; Chen, Shuo; Chen, Gang; Mao, Jun; Ren, Zhifeng

doi:10.1039/c8ee00112j

Cited by 224 publications

(179 citation statements)

References 30 publications

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“…From the energy dispersion Fig. 5 Diagram schematically describes the deep impurity level in n-type PbTe: a deep impurity level localizes in bandgap and traps electrons at 300 K; b deep impurity level releases electrons into conduction band at elevated temperature; c carrier density in both In-and Ga-doped ntype PbTe increases with increasing temperature; d temperature-dependent ZT values in In-and Ga-doped n-type PbTe 67,82 relationship, the m Ã b is defined by following equation:…”

Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

“…At low temperature, the impurity levels produced by Ga and In could trap free electrons and work as a charge reservoir. 67,82 With rising temperature, the trapped electrons will be released from the deep impurity levels into conduction band, finally increasing the carrier density as shown in Fig. 5b.…”

Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

“…80 Consequently, the dynamic doping extends ZT max in a larger temperature range, resulting in a large average ZT (ZT ave ). 67,82 The ZT ave over the entire working temperature range is important as it determines the thermoelectric conversion efficiency. 22 Similarly, Cr, 83 Fe, 84 Ti, 85 Sc 86 etc.…”

Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

“…53,65 On the contrary, because of the large offset between light (L) and heavy (Σ) conduction bands, it is challenging to achieve conduction bands convergence in n-type PbTe. However, the approaches of conduction band flattening 66 and introducing deep impurity level 67,68 could boost power factor in n-type PbTe. Apart from the discussions about electrical transport properties, we also put emphasis on suppressing phonon propagation through designing hierarchical architectures ranging from atomic-scale, nanoscale to mesoscale.…”

Section: Introductionmentioning

confidence: 99%

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Charge and phonon transport in PbTe-based thermoelectric materials

2018

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PbTe is a typical intermediate-temperature thermoelectric material, which has undergone extensive developments and achieved excellent high thermoelectric performance. In this perspective we summarized several strategies that were successfully applied in PbTe-based thermoelectric materials through manipulating charge and phonon transports, such as optimizing carrier density to tune Fermi level, tailoring band structure to enhance effective mass, and designing all-scale hierarchical architectures to suppress phonon propagation. Meanwhile, due to the different features of conduction and valence bands, we separately introduced the approaches to enhance performance of p-type and n-type PbTe. In p-type PbTe, the strategies of band convergence, band alignment and density of state (DOS) distortion are more effective to achieve high electrical transport properties. By contrast, flattening conduction bands and introducing deep impurity level are more suitable for n-type PbTe. Lastly, several potential strategies were proposed to further improve the thermoelectric performance of PbTe-based materials, which might be extended to other thermoelectric systems.

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Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

Section: Manipulations On Conduction Band Structure In N-type Pbtementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Charge and phonon transport in PbTe-based thermoelectric materials

2018

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“…Up to now, the multidoping (alloying) strategy has been demonstrated to be a highly effective approach in boosting the performance of the state-of-art bulk thermoelectric materials. For example, in order to obtain ultrahigh zT values, doping or alloying with at least two elements is necessary for the GeTe- [17,18], SnTe- [19,20], and PbTe- [21][22][23] based compounds. Apparently, it becomes increasingly difficult to achieve satisfactory compositions for the abovementioned system via serial experimental synthesis and characterization processes.…”

Section: Introductionmentioning

confidence: 99%

High Thermoelectric Performance of Cu-Doped PbSe-PbS System Enabled by High-Throughput Experimental Screening

You

et al. 2020

Research

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Recent advances in high-throughput (HTP) computational power and machine learning have led to great achievements in exploration of new thermoelectric materials. However, experimental discovery and optimization of thermoelectric materials have long relied on the traditional Edisonian trial and error approach. Herein, we demonstrate that ultrahigh thermoelectric performance in a Cu-doped PbSe-PbS system can be realized by HTP experimental screening and precise property modulation. Combining the HTP experimental technique with transport model analysis, an optimal Se/S ratio showing high thermoelectric performance has been efficiently screened out. Subsequently, based on the screened Se/S ratio, the doping content of Cu has been subtly adjusted to reach the optimum carrier concentration. As a result, an outstanding peak zT~1.6 is achieved at 873 K for a 1.8 at% Cu-doped PbSe0.6S0.4 sample, which is the superior value among the n-type Te-free lead chalcogenides. We anticipate that current work will stimulate large-scale unitization of the HTP experimental technique in the thermoelectric field, which can greatly accelerate the research and development of new high-performance thermoelectric materials.

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Thermoelectrics: From Thermoelectric Figure of Merit to Device Design

Xu¹,

Liang²,

Song³

et al. 2022

Digital Encyclopedia of Applied Physics

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Thermoelectrics is defined as direct energy conversion between the heat and electricity associated with thermoelectric power generation and refrigeration. Significant progress has been made in the theoretical understanding, materials and device preparation technology, and performance improvement of thermoelectrics since the Seebeck effect was found 200 years ago. Herein, the article starts with the basic physics concepts underlying the thermoelectric phenomenon, and the key descriptor for evaluating thermoelectric performance, the thermoelectric figure of merit ( ZT ), is introduced. The corresponding issues and strategies for pursuing higher ZT are discussed in detail, and a brief introduction of organic thermoelectric materials is given. The leading engineering challenges from the material to the device are further elaborated based on the state‐of‐the‐art device design. This article aims to provide the reader with a comprehensive overview of the scope of activities related to this area of scientific endeavor.

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Deep defect level engineering: a strategy of optimizing the carrier concentration for high thermoelectric performance

Abstract: Thermoelectric properties are heavily dependent on the carrier concentration, and therefore the optimization of carrier concentration plays a central role in achieving high thermoelectric performance.

Cited by 224 publications

References 30 publications

Charge and phonon transport in PbTe-based thermoelectric materials

Charge and phonon transport in PbTe-based thermoelectric materials

High Thermoelectric Performance of Cu-Doped PbSe-PbS System Enabled by High-Throughput Experimental Screening

Thermoelectrics: From Thermoelectric Figure of Merit to Device Design

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