Enhancing thermoelectric properties of BiCuSeO via uniaxial compressive strain: First-principles calculations

Tan, Rui; Zou, Chunpeng; Pan, Kai; Liu, Yunya

doi:10.1016/j.jallcom.2018.01.371

Cited by 16 publications

(2 citation statements)

References 47 publications

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“…Density function theory (DFT) has been adopted to calculate the lattice constants and electronic structures of BiCuOCh (Ch = Se, S) under strain constraint, which are implemented in the Vienna ab initio Simulation Package (VASP) [23][24][25][26]. The projector augmented wave (PAW) method is chosen with Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) exchange-correlation potential [27].…”

Section: Computational Detailsmentioning

confidence: 99%

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

2020

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It is well known that the performance of thermoelectric measured by figure of merit ZT linearly depends on electrical conductivity, while it is quadratic related to the Seebeck coefficient, and the improvement of Seebeck coefficient may reduce electrical conductivity. As a promising thermoelectric material, BiCuOCh (Ch = Se, S) possesses intrinsically low thermal conductivity, and comparing with its p-type counterpart, n-type BiCuOCh has superior electrical conductivity. Thus, a strategy for increasing Seebeck coefficient while almost maintaining electrical conductivity for enhancing thermoelectric properties of n-type BiCuOCh is highly desired. In this work, the effects of uniaxial tensile strain on the electronic structures and thermoelectric properties of n-type BiCuOCh are examined by using first-principles calculations combined with semiclassical Boltzmann transport theory. The results indicate that the Seebeck coefficient can be enhanced under uniaxial tensile strain, and the reduction of electrical conductivity is negligible. The enhancement is attributed to the increase in the slope of total density of states and the effective mass of electron, accompanied with the conduction band near Fermi level flatter along the Γ to Z direction under strain. Comparing with the unstrained counterpart, the power factor can be improved by 54% for n-type BiCuOSe, and 74% for n-type BiCuOS under a strain of 6% at 800 K with electron concentration 3 × 10 20 cm −3 . Furthermore, the optimal carrier concentrations at different strains are determined. These insights point to an alternative strategy for superior thermoelectric properties.Newly discovered thermoelectric materials BiCuOSe and BiCuOS [BiCuOCh (Ch = Se, S)] have attracted attentions due to their intrinsically low thermal conductivity [8][9][10][11], whose conductive layers (Cu 2 Se 2 ) 2− or (Cu 2 S 2 ) 2− are alternately stacked with an insulating layer (Bi 2 O 2 ) 2+ , composing of the ZrSiCuAs structure type, and this layered structure may be an important factor affording its low thermal conductivity [12,13]. Because of the low lattice thermal conductivity, efforts to improve thermoelectric performance ZT of these compounds have mainly focused on enhancing their power factor S 2 σ. To obtain high power factor, several approaches to increase the electrical conductivity of BiCuOCh, such as doping [14,15], pressure [16], and strain [17], have been attempted. As the electrical conductivity, σ, and Seebeck coefficient, S, are coupled, improving electrical conductivity will reduce Seebeck coefficient [1]. Compared with p-type BiCuOSe, n-type BiCuOSe possesses higher electrical conductivity [16]. On the other hand, it is also noticed that the power factor, S 2 σ, depends linearly on electrical conductivity, σ, but quadratically on Seebeck coefficient S. Thus, it is an alternative pathway to achieve the enhancement of power factor for n-type BiCuOCh via enhancing Seebeck coefficient while keeping electrical conductivity with only slight reduction.Recently, band engineer...

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Section: Computational Detailsmentioning

confidence: 99%

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

2020

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“…High-entropy GeTe-based thermoelectric materials exhibit high thermoelectric performance and efficient power generation. Its unique advantage is its ability to improve the thermoelectric figure of merit through synergistic optimization of electrons and phonons via high-entropy stabilization . The thermoelectric figure of merit of germanium telluride-based materials has been significantly enhanced, reaching a high ZT value of 2.7.…”

Section: Introductionmentioning

confidence: 99%

Interpretable Machine Learning Workflow for Evaluating and Analyzing the Performance of High-Entropy GeTe-Based Thermoelectric Materials

Li,

Liu

2023

ACS Appl. Electron. Mater.

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To guide the development of high-performance thermoelectric materials, it is essential to design appropriate material compositions and temperature environments. This study focuses on analyzing the properties of high-entropy GeTe-based thermoelectric materials under different temperature environments and chemical compositions using an interpretable machine learning workflow. First, an experimental dataset from previous research on thermoelectric materials is constructed, and descriptors based on atomic features are established. Feature selection techniques, such as Pearson correlation, univariate feature selection, and exhaustive feature selection, are applied to select relevant features. The selected features are then used in conjunction with the target variable, the ZT value, for training and testing. The effectiveness of the training is demonstrated by comparing the performance on the testing set and using cross-validation to identify the best machine learning model. Furthermore, the SHAP (SHapley Additive exPlanations) method is employed to interpret the best model. Through global interpretability, analysis of interactive variables' contributions to the target variable, and local interpretability methods, material selection, and performance optimization are carried out. The results reveal that temperature has the greatest impact on the ZT value of thermoelectric materials, while the effects of molar volume and electronegativity sequentially diminish. By utilizing interpretable machine learning methods, we are able to predict and optimize the performance of thermoelectric materials based on known samples. This not only facilitates the evaluation and prediction of the thermoelectric properties of materials but also provides a comprehensive research workflow design approach for guiding the selection and development of high-performance GeTe-based thermoelectric materials.

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Impact of Lattice Strain on the Electronic and Thermoelectric Properties of CoAs₃ Skutterudite Material

Mahi,

Meghoufel,

Mostefa

et al. 2024

Physica Status Solidi (b)

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Using density functional theory (DFT) combined with semi‐classical Boltzmann transport theory, the electronic and thermoelectric properties of binary skutterudite CoAs3 material are investigated up to 30 GPa. Elastic properties calculations confirm the mechanical stability at 0 GPa and under varying hydrostatic pressures, with ductility influenced by pressure. To ensure dynamical stability, the phonon dispersion frequencies are computed at both 0 and 30 GPa. Electronic band structure calculations, using the GGA + TB‐mBJ approximation, indicate that CoAs3 initially exhibits a direct band gap at its equilibrium lattice constant, which shifts to become indirect under increasing pressure. To assess the impact of pressure on the thermoelectric properties of CoAs3, the Seebeck coefficient, thermal conductivities, and figure of merit (ZT) are calculated at pressures of 5, 10, 20, and 30 GPa for various temperatures (300, 600, 900, and 1200 K). These computations provide valuable insights into how varying pressures influence the material's thermoelectric performance. The optimal thermoelectric properties in CoAs3 material are achieved at 5 GPa and 1200 K for n‐doping (20 GPa and 600 K for p‐doping), with an ideal doping concentration of 1.5 × 1021 cm−3 (5.5 × 1018 cm−3). Under these conditions, the material reaches a high figure of merit (ZT) value of 0.52 for n‐doping and 0.49 for p‐doping. These findings underscore CoAs3 as a promising candidate for applications in energy harvesting and optoelectronic systems, showcasing its robust thermoelectric performance under precise pressure and temperature conditions.

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Enhancing thermoelectric properties of BiCuSeO via uniaxial compressive strain: First-principles calculations

Cited by 16 publications

References 47 publications

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

Interpretable Machine Learning Workflow for Evaluating and Analyzing the Performance of High-Entropy GeTe-Based Thermoelectric Materials

Impact of Lattice Strain on the Electronic and Thermoelectric Properties of CoAs₃ Skutterudite Material

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Enhancing thermoelectric properties of BiCuSeO via uniaxial compressive strain: First-principles calculations

Cited by 16 publications

References 47 publications

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

Uniaxial Tensile Strain Induced the Enhancement of Thermoelectric Properties in n-Type BiCuOCh (Ch = Se, S): A First Principles Study

Interpretable Machine Learning Workflow for Evaluating and Analyzing the Performance of High-Entropy GeTe-Based Thermoelectric Materials

Impact of Lattice Strain on the Electronic and Thermoelectric Properties of CoAs3 Skutterudite Material

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Impact of Lattice Strain on the Electronic and Thermoelectric Properties of CoAs₃ Skutterudite Material