The n- and p-type thermoelectric response of a semiconducting Co-based quaternary Heusler alloy: a density functional approach

2019 ◽  
Vol 7 (25) ◽  
pp. 7664-7671 ◽  
Author(s):  
Enamullah Enamullah ◽  
Pil-Ryung Cha

In the combined framework of density functional and Boltzmann transport theory, we have systematically studied the electronic structure, mechanical stability and thermoelectric properties of the semiconducting quaternary Heusler alloy, CoFeTiAl.

2013 ◽  
Vol 1543 ◽  
pp. 23-28 ◽  
Author(s):  
Liwen F. Wan ◽  
Scott P. Beckman

ABSTRACTIn this work, the thermoelectric properties of Se-doped Bi2Te3 are examined using first-principles density functional theory and semi-classical Boltzmann transport theory. Placing a single Se atom on the 3a Wyckoff position lowers the unit cell energy by approximately 3.6 eV, compared to the 6c Te position. The electronic structure of Bi2Te3 has minor changes upon Se doping. At carrier concentration of 1019 cm-3, the optimal thermopower, S, is obtained as 207 and 220 μV/K for n-type and p-type doping, respectively. Unlike the thermopower, the power factor, S2σ/τ, is highly anisotropic for the in-plane and cross-plane conduction. At carrier concentrations of 1019 cm-3, the best power factor is predicted to be around 1.05 and 1.4×1011 W/m·s·K2 for n-type and p-type doping, respectively.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ning Wang ◽  
Menglu Li ◽  
Haiyan Xiao ◽  
Zhibin Gao ◽  
Zijiang Liu ◽  
...  

AbstractBand degeneracy is effective in optimizing the power factors of thermoelectric (TE) materials by enhancing the Seebeck coefficients. In this study, we demonstrate this effect in model systems of layered oxyselenide family by the density functional theory (DFT) combined with semi-classical Boltzmann transport theory. TE transport performance of layered LaCuOSe and BiCuOSe are fully compared. The results show that due to the larger electrical conductivities caused by longer electron relaxation times, the n-type systems show better TE performance than p-type systems for both LaCuOSe and BiCuOSe. Besides, the conduction band degeneracy of LaCuOSe leads to a larger Seebeck coefficient and a higher optimal carrier concentration than n-type BiCuOSe, and thus a higher power factor. The optimal figure of merit (ZT) value of 1.46 for n-type LaCuOSe is 22% larger than that of 1.2 for n-type BiCuOSe. This study highlights the potential of wide band gap material LaCuOSe for highly efficient TE applications, and demonstrates that inducing band degeneracy by cations substitution is an effective way to enhance the TE performance of layered oxyselenides.


2021 ◽  
Author(s):  
Megha Goyal ◽  
M.M. Sinha

Abstract Heusler compounds are a tuneable class of material with a cubic crystal structure that can serve as a platform to study the topological phase of a material. These materials have numerous technological and scientific applications. So, in the present work, the mechanical, thermodynamical, and thermoelectric properties of LaAuPb in the topological phase have been reported by using density functional theory and Boltzmann transport theory. LaAuPb is mechanically stable, and the Poisson ratio reveals its ductile nature. The specific heat of the proposed compound at room temperature is 73.94 J K-1 mol-1 at constant volume. Debye’s temperature is estimated to be 188.64K. Moreover, the lattice thermal conductivity of the compound is 14.64 W/mK and 3.66 W/mK at 300K and 1200K, respectively. Good thermoelectric response of LaAuPb can be confirmed by its high value of the figure of merit (0.46) at 1200K. Hence, it is a potential material for thermoelectric applications. This work will help future researchers to better understand the stability, nature and behaviour of LaAuPb in material fabrication.


RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25900-25911 ◽  
Author(s):  
Esmaeil Pakizeh ◽  
Jaafar Jalilian ◽  
Mahnaz Mohammadi

In this study, based on the density functional theory and semi-classical Boltzmann transport theory, we investigated the structural, thermoelectric, optical and phononic properties of the Fe2ZrP compound.


2018 ◽  
Vol 5 (3) ◽  
pp. 171827 ◽  
Author(s):  
Daifeng Zou ◽  
Chuanbin Yu ◽  
Yuhao Li ◽  
Yun Ou ◽  
Yongyi Gao

The electronic structures of monolayer and bilayer SnSe 2 under pressure were investigated by using first-principles calculations including van der Waals interactions. For monolayer SnSe 2 , the variation of electronic structure under pressure is controlled by pressure-dependent lattice parameters. For bilayer SnSe 2 , the changes in electronic structure under pressure are dominated by intralayer and interlayer atomic interactions. The n -type thermoelectric properties of monolayer and bilayer SnSe 2 under pressure were calculated on the basis of the semi-classical Boltzmann transport theory. It was found that the electrical conductivity of monolayer and bilayer SnSe 2 can be enhanced under pressure, and such dependence can be attributed to the pressure-induced changes of the Se–Sn antibonding states in conduction band. Finally, the doping dependence of power factors of n -type monolayer and bilayer SnSe 2 at three different pressures were estimated, and the results unveiled that thermoelectric performance of n -type monolayer and bilayer SnSe 2 can be improved by applying external pressure. This study benefits to understand the nature of the transport properties for monolayer and bilayer SnSe 2 under pressure, and it offers valuable insight for designing high-performance thermoelectric few-layered SnSe 2 through strain engineering induced by external pressure.


2017 ◽  
Vol 31 (29) ◽  
pp. 1750265 ◽  
Author(s):  
Guangtao Wang ◽  
Dongyang Wang ◽  
Xianbiao Shi ◽  
Yufeng Peng

We studied the crystal and electronic structures of LaOBiSSe and LaOBiSeS using first-principles calculations and confirmed that the LaOBiSSe (S atoms on the top of BiCh2 layer and Se atoms in the inner of it) is the stable structure. Then we calculate the thermoelectric properties of LaOBiSSe using the standard Boltzmann transport theory. The in-plane thermoelectric performance are better than that along the c-axis in this n-type material. The in-plane power factor [Formula: see text] of n-type LaOBiSSe is as high as 12 [Formula: see text]W/cmK2 at 900 K with figure of merit ZT = 0.53 and [Formula: see text]. The ZT maximum appears around [Formula: see text] in a wide temperature region. The results indicate that LaOBiSSe is a 2D material with good thermal performance in n-type doping.


RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28501-28508
Author(s):  
Yang Hu ◽  
Yurong Jin ◽  
Guangbiao Zhang ◽  
Yuli Yan

We investigate the transport properties of bulk Ca2YZ (Y = Au, Hg; Z = As, Sb, Bi, Sn and Pb) by a combination method of first-principles and Boltzmann transport theory.


2019 ◽  
Vol 21 (2) ◽  
pp. 851-858 ◽  
Author(s):  
Xiuxian Yang ◽  
Zhenhong Dai ◽  
Yinchang Zhao ◽  
Wenchao Niu ◽  
Jianye Liu ◽  
...  

We have used first principle calculations together with Boltzmann transport theory to calculate the electronic structure and thermoelectric properties of CoSb3 and IrSb3.


2013 ◽  
Vol 06 (05) ◽  
pp. 1340013 ◽  
Author(s):  
DAVID J. SINGH ◽  
DAVID PARKER

We report calculations of the doping and temperature dependent thermopower of Ru 2 Si 3 based on Boltzmann transport theory and the first principles electronic structure. We find that the performance reported to date can be significantly improved by optimization of the doping level and that ultimately n-type should have higher ZT than p-type.


2021 ◽  
Vol 7 ◽  
Author(s):  
Liangshuang Fan ◽  
Hengyu Yang ◽  
Guofeng Xie

Recently, monolayer of triphosphides (e.g., InP3, SnP3, and GaP3) attracts much attention due to their good thermoelectric performance. Herein, we predict a novel triphosphide monolayer AsP3 and comprehensively investigate its thermoelectric properties by combining first-principles calculations and semiclassical Boltzmann transport theory. The results show that AsP3 monolayer has an ultralow thermal conductivity of 0.36 and 0.55 Wm K−1 at room temperature along the armchair and zigzag direction. Surprisingly, its maximum Seebeck coefficient in the p-type doping reaches 2,860 µVK−1. Because of the ultralow thermal conductivity and ultrahigh Seebeck coefficient, the thermoelectric performance of AsP3 monolayer is excellent, and the maximum ZT of p-type can reach 3.36 at 500 K along the armchair direction, which is much higher than that of corresponding bulk AsP3 at the same temperature. Our work indicates that the AsP3 monolayer is the promising candidate in TE applications and will also stimulate experimental scientists’ interest in the preparation, characterization, and thermoelectric performance tuning.


Sign in / Sign up

Export Citation Format

Share Document