scholarly journals Co-regulation of the copper vacancy concentration and point defects leading to the enhanced thermoelectric performance of Cu3In5Te9-based chalcogenides

RSC Advances ◽  
2019 ◽  
Vol 9 (54) ◽  
pp. 31747-31752 ◽  
Author(s):  
Min Li ◽  
Yong Luo ◽  
Xiaojuan Hu ◽  
Zhongkang Han ◽  
Xianglian Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Carrier Concentration ◽  
Point Defects ◽  
Lattice Thermal Conductivity ◽  
Vacancy Concentration ◽  
Thermoelectric Performance ◽  
High Carrier Concentration ◽  
High Carrier

Co-regulation of both the copper vacancy concentration (Vc) and point defect GaIn realizing the high carrier concentration and low lattice thermal conductivity in Cu3In5Te9-based chalcogenides simultaneously.

scholarly journals Silver vacancy concentration engineering leading to the ultralow lattice thermal conductivity and improved thermoelectric performance of Ag1-xInTe2

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yaqiong Zhong ◽  
Yong Luo ◽  
Xie Li ◽  
Jiaolin Cui
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Point Defects ◽  
Lattice Thermal Conductivity ◽  
Vacancy Concentration ◽  
Antisite Defect ◽  
Thermoelectric Performance ◽  
Callaway Model

AbstractAgInTe2 compound has not received enough recognition in thermoelectrics, possibly due to the fact that the presence of Te vacancy (VTe) and antisite defect of In at Ag site (InAg) degrades its electrical conductivity. In this work, we prepared the Ag1-xInTe2 compounds with substoichiometric amounts of Ag and observed an ultralow lattice thermal conductivity (κL = 0.1 Wm−1K−1) for the sample at x = 0.15 and 814 K. This leads to more than 2-fold enhancement in the ZT value (ZT = 0.62) compared to the pristine AgInTe2. In addition, we have traced the origin of the untralow κL using the Callaway model. The results attained in this work suggest that the engineering of the silver vacancy (VAg) concentration is still an effective way to manipulate the thermoelectric performance of AgInTe2, realized by the increased point defects and modified crystal structure distortion as the VAg concentration increases.

Enhanced Thermoelectric Performance via Oxygen Manipulation in BiCuTeO

MRS Advances ◽  
2019 ◽  
Vol 4 (08) ◽  
pp. 499-505 ◽  
Author(s):  
Hui-Ching Chang ◽  
Hao-Jen You ◽  
Raman Sankar ◽  
Ying-Jay Yang ◽  
Li-Chyong Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Grain Size ◽  
Solid State ◽  
Oxygen Content ◽  
Lattice Thermal Conductivity ◽  
Oxygen Deficiency ◽  
Thermoelectric Performance ◽  
High Carrier Concentration ◽  
Press Method ◽  
High Carrier

AbstractBiCuTeO is a potential thermoelectric material owing to its low thermal conductivity and high carrier concentration. However, the thermoelectric performance of BiCuTeO is still below average and has much scope for improvement. In this study, we manipulated the nominal oxygen content in BiCuTeO and synthesized BiCuTeOx (x = 0.94–1.06) bulks by a solid-state reaction and pelletized them by a cold-press method. The power factor was enhanced by varying the nominal oxygen deficiency due to the increased Seebeck coefficient. The thermal conductivity was also reduced due to the decrease in lattice thermal conductivity owing to the small grain size generated by the optimal nominal oxygen content. Consequently, the ZT value was enhanced by ∼11% at 523 K for stoichiometric BiCuTeO0.94 compared to BiCuTeO. Thus, optimal oxygen manipulation in BiCuTeO can enhance the thermoelectric performance. This study can be applied to developing oxides with high thermoelectric performances.

scholarly journals Synergistic boost of output power density and efficiency in In-Li–codoped SnTe

2019 ◽  
Vol 116 (44) ◽  
pp. 21998-22003 ◽  
Author(s):  
Fengkai Guo ◽  
Haijun Wu ◽  
Jianbo Zhu ◽  
Honghao Yao ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Power Density ◽  
Output Power ◽  
Traditional Method ◽  
Lattice Thermal Conductivity ◽  
Heat Output ◽  
Leg Length ◽  
Temperature Dependent ◽  
High Carrier Concentration ◽  
High Carrier

We report enhanced thermoelectric performance of SnTe by further increasing its intrinsic high carrier concentration caused by Sn vacancies in contrast to the traditional method. Along with In2Te3 alloying, which results in an enhanced Seebeck coefficient, Li2Te is added to further increase the carrier concentration in order to maintain high electrical conductivity. Finally, a relatively high PFave of ∼28 μW cm−1 K−2 in the range between 300 and 873 K is obtained in an optimized SnTe-based compound. Furthermore, nanoprecipitates with extremely high density are constructed to scatter phonons strongly, resulting in an ultralow lattice thermal conductivity of ∼0.45 W m−1 K−1 at 873 K. Given that the Z value is temperature dependent, the (ZT)eng and (PF)eng values are adopted to accurately predict the performance of this material. Taking into account the Joule and Thomson heat, output power density of ∼5.53 W cm−2 and leg efficiency of ∼9.6% are calculated for (SnTe)2.94(In2Te3)0.02-(Li2Te)0.045 with a leg length of 4 mm and cold- and hot-side temperatures of 300 and 870 K, respectively.

scholarly journals Achieving High Thermoelectric Performance in Rare-Earth Element-Free CaMg2Bi2 with High Carrier Mobility and Ultralow Lattice Thermal Conductivity

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Muchun Guo ◽  
Fengkai Guo ◽  
Jianbo Zhu ◽  
Li Yin ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Materials ◽  
Carrier Mobility ◽  
Lattice Thermal Conductivity ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Widespread Application ◽  
Compatibility Factor ◽  
High Carrier Mobility ◽  
High Carrier

CaMg2Bi2-based compounds, a kind of the representative compounds of Zintl phases, have uniquely inherent layered structure and hence are considered to be potential thermoelectric materials. Generally, alloying is a traditional and effective way to reduce the lattice thermal conductivity through the mass and strain field fluctuation between host and guest atoms. The cation sites have very few contributions to the band structure around the fermi level; thus, cation substitution may have negligible influence on the electric transport properties. What is more, widespread application of thermoelectric materials not only desires high ZT value but also calls for low-cost and environmentally benign constituent elements. Here, Ba substitution on cation site achieves a sharp reduction in lattice thermal conductivity through enhanced point defects scattering without the obvious sacrifice of high carrier mobility, and thus improves thermoelectric properties. Then, by combining further enhanced phonon scattering caused by isoelectronic substitution of Zn on the Mg site, an extraordinarily low lattice thermal conductivity of 0.51 W m-1 K-1 at 873 K is achieved in (Ca0.75Ba0.25)0.995Na0.005Mg1.95Zn0.05Bi1.98 alloy, approaching the amorphous limit. Such maintenance of high mobility and realization of ultralow lattice thermal conductivity synergistically result in broadly improvement of the quality factor β. Finally, a maximum ZT of 1.25 at 873 K and the corresponding ZTave up to 0.85 from 300 K to 873 K have been obtained for the same composition, meanwhile possessing temperature independent compatibility factor. To our knowledge, the current ZTave exceeds all the reported values in AMg2Bi2-based compounds so far. Furthermore, the low-cost and environment-friendly characteristic plus excellent thermoelectric performance also make the present Zintl phase CaMg2Bi2 more competitive in practical application.

Extraordinary role of Zn in enhancing thermoelectric performance of Ga-doped n-type PbTe

2022 ◽  
Author(s):  
Zhong-zhen Luo ◽  
Songting Cai ◽  
Shiqiang Hao ◽  
Trevor Bailey ◽  
Yubo Luo ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Lattice Thermal Conductivity ◽  
Thermoelectric Performance ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Ga Doping ◽  
Role Of Zn

Although Ga doping can weaken the electron phonon coupling of n-type PbTe, Ga-doped PbTe has a relatively low carrier concentration (n) and high lattice thermal conductivity (κlat), resulting in a...

The study of structural, electronic and thermoelectric properties of Ca1−xYbxZn2Sb2 (x = 0, 0.25, 0.5, 0.75, 1) Zintl compounds

2021 ◽  
pp. 2150100
Author(s):  
I. Mili ◽  
H. Latelli ◽  
T. Ghellab ◽  
Z. Charifi ◽  
H. Baaziz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Figure Of Merit ◽  
Narrow Gap ◽  
High Carrier Concentration ◽  
Merit Factor ◽  
Composition Formula ◽  
High Seebeck Coefficient ◽  
High Carrier

Based on the electronic structure, the physical properties of [Formula: see text] ([Formula: see text], 0.25, 0.5, 0.75, 1) Zintl compounds are studied. The transport properties can be significantly changed by varying the composition [Formula: see text]. The materials under study are more metallic with increasing [Formula: see text] and behaves like a semiconductor when [Formula: see text] decreases. It is found that [Formula: see text] exhibits a larger thermopower magnitude ([Formula: see text] at [Formula: see text] and the Seebeck coefficient decreases as [Formula: see text] increases. The calculated figure of merit factor of [Formula: see text] is found to be low, this is explained by the fact that its structure is very compact and its bandgap is small which lead to high electrical and thermal conductivity due to high carrier concentration ([Formula: see text] at [Formula: see text]). On other hand a narrow-gap (0.46 eV for [Formula: see text]), provides a balance between a high Seebeck coefficient and low electronic thermal conductivity, with a slight increase in the carrier concentration when the temperature increases ([Formula: see text] at 600 K). As a consequence, [Formula: see text] compound is predicted to have good performance for thermoelectric applications. The electrical [Formula: see text] and the thermal [Formula: see text] conductivity for [Formula: see text] compound in both directions (along [Formula: see text] and [Formula: see text]-axes) are calculated. It is obtained that [Formula: see text] is 120% of [Formula: see text] at high-temperature, whereas [Formula: see text] Seebeck coefficient was higher than [Formula: see text] especially at [Formula: see text] ([Formula: see text]. The large value of [Formula: see text] showed that the transport is dominated by zz-axis.

Sign in / Sign up

Export Citation Format

Share Document