Investigation of Structural, Electronic and Thermoelectric Properties of Two-Dimensional Graphdiyne/Borophene Monolayers and Hetero-bilayers

2021 ◽  
Author(s):  
Seifollah Jalili ◽  
Atena Pakzadiyan
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
2D Materials ◽  
Structural Models ◽  
Two Dimensional ◽  
Metallic Behavior ◽  
Higher Power ◽  
Binding Energy Calculations ◽  
Conductivity Behavior

Abstract The integration of dissimilar 2D materials is important for nanoelectronic and thermoelectric applications. Among different polymorphs and different bond geometries, borophene and graphdiyne are two promising candidates for these applications. In the present paper, we have studied hetero-bilayers comprising graphdiyne-borophene (GDY-BS) sheets. Three structural models, namely S0, S1 and S2 have been used for borophene sheets. The optimum interlayer distance for the hetero-bilayers was obtained through binding energy calculations. Then, the structure and electronic properties of the monolayers and hetero-bilayers were individually examined and compared. Graphdiyne monolayer was shown to be a semiconductor with a band gap of 0.43 eV, while the borophene monolayers, as well as all studied hetero-bilayers showed metallic behavior. The thermoelectric properties of borophene and graphdiyne monolayers and the graphdiyne-borophene bilayers were calculated on the basis of the semi-classical Boltzmann theory. The results showed signs of improvement in the conductivity behavior of the hetero-bilayers. Furthermore, considering the increase in Seebeck coefficient and the conductivity for all the structures after calculating figure of merit and power factor, a higher power factor and more energy generation were observed for bilayers. These results show that the GDY-BS hetero-bilayers can positively affect the performance of thermoelectric devices,

First principle investigation of stuctural, electronic, and thermoelectric properties of Ga1-xInxP (x = 0.0 to 1.0) alloys

2022 ◽  
Author(s):  
Abeer AlObaid
Keyword(s):  
Electrical Conductivity ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
First Principle ◽  
Group Iii V Semiconductors ◽  
Thermoelectric Devices ◽  
Group Iii ◽  
Maximum Value

Abstract Group III-V semiconductors are extensively studied for various technological applications. Different properties of Ga1-xInxP such as electronic, optical, elastic, thermal and mechanical, etc. were studied under different concentrations. However, there is no evident for thermoelectric performance of Ga1-xInxP (x = 0.0, 0.25, 0.50, 0.75 and 1.0). In the present study, we have calculated the structural, electronic and thermoelectric behavior of Ga1-xInxP by utilizing the WIEN2K package. The InP show indirect semiconductor nature of band gap of 2.1 eV. By adding the concentration of In, the band gap nature shifts from indirect to direct with a decrease in the band gap. For thermoelectric properties, Seebeck, thermal and electrical conductivity, power factor and figure of merit ZT are investigated through the BoltzTraP code. Our study reveals that Ga1-xInxP has a maximum value of ZT=0.79 at x=1, provide an opportunity for developing good thermoelectric devices.

scholarly journals Is LiI a Potential Dopant Candidate to Enhance the Thermoelectric Performance in Sb-Free GeTe Systems? A Prelusive Study

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 643 ◽  
Author(s):  
Bhuvanesh Srinivasan ◽  
David Berthebaud ◽  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Short Communication ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Plasma Sintering ◽  
Spark Plasma

As a workable substitute for toxic PbTe-based thermoelectrics, GeTe-based materials are emanating as reliable alternatives. To assess the suitability of LiI as a dopant in thermoelectric GeTe, a prelusive study of thermoelectric properties of GeTe1−xLiIx (x = 0–0.02) alloys processed by Spark Plasma Sintering (SPS) are presented in this short communication. A maximum thermoelectric figure of merit, zT ~ 1.2, was attained at 773 K for 2 mol% LiI-doped GeTe composition, thanks to the combined benefits of a noted reduction in the thermal conductivity and a marginally improved power factor. The scattering of heat carrying phonons due to the presumable formation of Li-induced “pseudo-vacancies” and nano-precipitates contributed to the conspicuous suppression of lattice thermal conductivity, and consequently boosted the zT of the Sb-free (GeTe)0.98(LiI)0.02 sample when compared to that of pristine GeTe and Sb-rich (GeTe)x(LiSbTe2)2 compounds that were reported earlier.

scholarly journals Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi2Te3 matrix

2019 ◽  
Vol 10 ◽  
pp. 634-643 ◽  
Author(s):  
Srashti Gupta ◽  
Dinesh Chandra Agarwal ◽  
Bathula Sivaiah ◽  
Sankarakumar Amrithpandian ◽  
Kandasami Asokan ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Transmission Electron ◽  
High Power Factor ◽  
Different Temperatures ◽  
High Figure ◽  
Filtering Effect ◽  
P Type ◽  
20 Nm

The present study aims to see the enhancement in thermoelectric properties of bismuth telluride (Bi2Te3) annealed at different temperatures (573 and 773 K) through silver (Ag) nano-inclusions (0, 2, 5, 10, 15 and 20 wt %). Transmission electron microscopy (TEM) images of Ag incorporated in Bi2Te3 annealed at 573 K shows tubular, pentagonal, trigonal, circular and hexagonal nanoparticles with sizes of 6–25 nm (for 5 wt % Ag ) and 7–30 nm (for 20 wt % Ag). Ag incorporated in Bi2Te3 annealed at 773 K shows mainly hexagonally shaped structures with particle sizes of 2–20 nm and 40–80 nm (for 5 wt % Ag) and 10–60 nm (for 20 wt % Ag). Interestingly, the samples annealed at 573 K show the highest Seebeck coefficient (S, also called thermopower) at room temperature (p-type behavior) for 5% Ag which is increased ca. five-fold in comparison to Ag-free Bi2Te3, whereas for samples with the same content (5% Ag) annealed at 773 K the increment in thermopower is only about three-fold with a 6.9-fold enhancement of the power factor (S 2σ). The effect of size and shape of the nanoparticles on thermoelectric properties can be understood on the basis of a carrier-filtering effect that results in an increase in thermopower along with a control over the reduction in electrical conductivity to maintain a high power factor yielding a high figure of merit.

Optimization of Thermoelectric Properties of Ni-Cu based Alloy through Combinatorial Approach

2007 ◽  
Vol 1044 ◽  
Author(s):  
Atsushi Yamamoto ◽  
Haruhiko Obara ◽  
Kazuo Ueno
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Combinatorial Library ◽  
Parallel Synthesis ◽  
The Other ◽  
Material System ◽  
Combinatorial Approach ◽  
Large Power

AbstractThe thermoelectric properties of Ni1-xCux (0<x<1) alloy are measured from 323K to 950K. The sample with optimized composition, Ni70Cu30 is found to possess large power factor value of 0.012 Wm−1K−2 at around 950K. Estimated figure of merit value ZT is 0.21 for Ni50Cu50 and 0.18 for Ni70Cu30 at the same temperature. A novel attempt of high-throughput parallel synthesis using multiple-wells is carried out to test the feasibility of combinatorial approach in this material system. The Seebeck coefficient is visualized over the multiple-wells combinatorial library and the other Ni-Cu composition-spread, and it is proved that further enhancement of throughput could be possible by conducting systematic experiments based on the combinatorial approaches performed in this study.

scholarly journals Improved Thermoelectric Performance in N-Type Half-Heusler NbCoSn by Heavy-Element Pt Doping

2020 ◽  
Author(s):  
Federico Serrano Sanchez ◽  
Ting Luo ◽  
Junjie Yu ◽  
Wenjie Xie ◽  
Gudrun Auffermann ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Carrier Mobility ◽  
Figure Of Merit ◽  
Heavy Element ◽  
Lattice Thermal Conductivity ◽  
Electrical Power ◽  
Heusler Compounds ◽  
Strong Point

Half-Heusler compounds with a valence electron count of 18, including ZrNiSn, ZrCoSb, and NbFeSb, are good thermoelec-tric materials owing to favourable electronic structures. Previous computational studies had predicted a high electrical power factor in another half-Heusler compound NbCoSn, but it has not been extensively investigated experimentally. Herein, the synthesis, structural characterization, and thermoelectric properties of the heavy-element Pt-doped NbCoSn compounds are reported. Pt is found to be an effective dopant enabling the optimization of electrical power factor, simul-taneously leading to a strong point defect scattering of phonons, and thereby suppressing the lattice thermal conductivity. Annealing significantly improves the carrier mobility, which is ascribed to the decreased grain boundary scattering. As a result, a maximum power factor of ~3.4 mWm-1K-2 is obtained at 600 K. In conjunction with the reduced lattice thermal conductivity, a maximum figure of merit zT of ~0.6 is achieved at 773 K for the post-annealed NbCo0.95Pt0.05Sn, an increase of 100% compared to the undoped NbCoSn. This work highlights the important roles of the doping element and micro-structure on the thermoelectric properties of half-Heusler compounds<br><p></p>

scholarly journals Effects of Ge Doping on the Charge Transport and Thermoelectric Properties of Permingeatites Cu3Sb1−yGeySe4

2021 ◽  
Vol 59 (6) ◽  
pp. 422-429
Author(s):  
Ji-Hee Pi ◽  
Go-Eun Lee, ◽  
Il-Ho Kim
Keyword(s):  
Thermal Conductivity ◽  
Charge Transport ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Lorenz Number ◽  
Degenerate Semiconductor ◽  
Thermoelectric Figure ◽  
Ge Doping

Permingeatites Cu3Sb1−yGeySe4 (0 ≤ y ≤ 0.14) were synthesized by mechanical alloying and hot pressing. The charge-transport parameters (Hall coefficient, carrier concentration, mobility, and Lorenz number) and thermoelectric properties (electrical conductivity, Seebeck coefficient, power factor, thermal conductivity, and figure of merit) were examined with respect to the Ge doping level. A single permingeatite phase with a tetragonal structure was obtained without subsequent heat treatment, but a small amount of the secondary phase Cu2GeSe3 was found for the specimens with y ≥ 0.08. All hot-pressed compacts exhibited a relative density of 97.5%–98.3%. The lattice constants of the a-axis and c-axis were decreased by the substitution of Ge at the Sb sites. As the Ge content increased, the carrier concentration increased from 5.2 × 1018 to 1.1 × 1020 cm−3, but the mobility decreased from 92 to 25 cm2·V−1·s−1. The Lorenz number of the undoped Cu3SbSe4 implied a non-degenerate semiconductor behavior, ranging from (1.57–1.56) × 10−8 V2·K−2 at 323–623 K. The thermoelectric figure of merit was 0.39 at 623 K, resulting from a power factor of 0.49 mW·m−1·K−2 and a thermal conductivity of 0.76 W·m−1·K−1. However, the Lorenz numbers of the Gedoped specimens indicated degenerate semiconductor characteristics, increasing to (1.63–1.94) × 10−8 V2·K−2 at 323–623 K. The highest thermoelectric figure of merit of 0.65 was at 623 K for Cu3Sb0.86Ge0.14Se4, resulting from the significantly improved power factor of 0.93 mW·m−1·K−2 and the thermal conductivity of 0.89W·m−1·K−1. As a result, the thermoelectric properties were remarkably enhanced by doping Ge into the Sb sites of the permingeatite.

Effects of one- and two-dimensional carbon hybridization of PEDOT:PSS on the power factor of polymer thermoelectric energy conversion devices

2015 ◽  
Vol 3 (12) ◽  
pp. 6526-6533 ◽  
Author(s):  
Dohyuk Yoo ◽  
Jeonghun Kim ◽  
Seung Hwan Lee ◽  
Wonseok Cho ◽  
Hyang Hee Choi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Conducting Polymers ◽  
Energy Conversion ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Two Dimensional ◽  
Thermoelectric Energy Conversion ◽  
Thermoelectric Energy ◽  
Polymer Thermoelectric ◽  
Energy Conversion Devices

Synergic effects of conducting polymers, carbon nanotubes, and graphene result in the enhanced thermoelectric properties of nanocomposites.

scholarly journals Enhanced mechanism of thermoelectric performance of Bi2Se3 using density functional theory

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Muhammad Zamir Mohyedin ◽  
Mohamad Fariz Mohamad Taib ◽  
Afiq Radzwan ◽  
M. Mustaffa ◽  
Amiruddin Shaari ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Effective Mass ◽  
Thermoelectric Properties ◽  
Density Of States ◽  
Power Factor ◽  
Figure Of Merit ◽  
Density Functional ◽  
Thermoelectric Performance ◽  
Boltzmann Transport ◽  
Functional Theory

Abstract Good thermoelectric performance is being sought to face major problems related to energy, especially in the concern of the usage of energy on environmental impact. In this work, we investigate the underlying mechanism to enhance the thermoelectric performance of bismuth selenide (Bi2Se3) by employing density functional theory (DFT) followed by the Boltzmann transport equation under relaxation time approximation. The structural, electronic, and thermoelectric properties were calculated and analyzed. From the analysis of combined results of thermoelectric properties and electronic properties as the function of the Fermi level, we found that the power factor of Bi2Se3 is improved by increasing electrical conductivity that contributed by the large density of states and light effective mass of charge carriers. The figure of merit, on the other hand, is enhanced by increasing Seebeck coefficient that contributed by heavy effective mass and decreasing thermal conductivity that contributed by low density of states. We also found that both power factor and figure of merit can be improved through n-type doping at 300 K and p-type doping at higher temperature (400 K and 500 K).

Effects of Oxygen-Reduction on Thermoelectric Properties of Sr0.61Ba0.39Nb2O6 Ceramics

2014 ◽  
Vol 787 ◽  
pp. 210-214 ◽  
Author(s):  
Yi Li ◽  
Jian Liu ◽  
Chun Lei Wang ◽  
Wen Bin Su ◽  
Yuan Hu Zhu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Oxygen Reduction ◽  
Thermoelectric Power ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Power Factor

The thermoelectric properties of Sr0.61Ba0.39Nb2O6 ceramics, reduced in various conditions, were investigated in the temperature range from 323K to 1073K. Both the electrical resistivity and the absolute Seebeck coefficient decreased with the deepening degree of oxygen-reduction. However, the decrease of the electrical resistivity had a major influence on the thermoelectric power factor. Therefore, the more heavily reduced sample can gain the higher value of thermoelectric power factor. It has been observed that the thermal conductivity increased with the deepening degree of oxygen-reduction, which indicates that the scattering of the oxygen vacancies produced by reduction does not play a dominant role in the thermal conduction. In spite of the increase of the thermal conductivity, the oxygen-reduction still promoted the thermoelectric figure of merit via the increase of the thermoelectric power factor. And the most heavily reduced Sr0.61Ba0.39Nb2O6 ceramic has the highest thermoelectric figure of merit (~0.18 at 1073 K) among all the samples.

Fabrication of Mg2Si from a Reused-silicon Source and its Thermoelectric Characteristics

2007 ◽  
Vol 1044 ◽  
Author(s):  
Masayasu Akasaka ◽  
Tsutomu Iida ◽  
Youhiko Mito ◽  
Takeru Omori ◽  
Yohei Oguni ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Silicon Source ◽  
Figures Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type ◽  
Type Sample

AbstractPolycrystalline Mg2Si was fabricated from a reused-Silicon source, based on Si sludge, using Spark Plasma Sintering technique. The n-type and p-type dopants, bismuth (Bi) and silver (Ag), respectively, were incorporated into the Mg2Si. The thermoelectric properties were estimated from 300 to 873K. The power factors of undoped and Bi-doped samples from the reused-Si source were comparable to those from a solar grade Si source (99.99999%). The power factor was estimated to be 2.5 × 10-5 W/cmK2 for the Bi-doped sample from the reused-Si source. However, the power factor of the Ag-doped, p-type sample from the reused-Si source was lower than that from solar grade Si source. The dimensionless figures of merit of samples from the resused-Si source were slightly lower than those from a solar grade Si source. The dimensionless figure of merit was estimated to be 0.53 at 812 K for Bi-doped sample from the reused-Si source.

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