Enhanced Thermoelectric Properties of Cu3SbSe4 Compounds by Isovalent Bismuth Doping

Author(s):  
Lijun Zhao ◽  
Mingyuan Wang ◽  
Jian Yang ◽  
Jiabin Hu ◽  
Yuan Zhu ◽  
...  

Abstract Cu3SbSe4, featuring its earth-abundant, cheap, nontoxic and environmentally-friendly constituent elements, can be considered as a promising intermediate temperature thermoelectric (TE) material. Herein, a series of p-type Bi-doped Cu3Sb1 − xBixSe4 (x = 0-0.04) samples were fabricated through melting and hot pressing (HP) process, and the effects of isovalent Bi-doping on their TE properties were comparatively investigated by experimental and computational methods. TEM analysis indicates that Bi-doped samples consist of Cu3SbSe4 and Cu2 − xSe impurity phases, which is in good agreement with the results of XRD, SEM and XPS. For Bi-doped samples, the reduced electrical resistivity (ρ) caused by the optimized carrier concentrations and enhanced Seebeck coefficient derived from the densities of states near the Fermi level give rise to a high power factor of ~ 1000 µWcm− 1K− 2 at 673 K for the Cu3Sb0.985Bi0.015Se4 sample. Additionally, the multiscale defects of Cu3SbSe4-based materials involving point defects, nanoprecipitates, amorphous phases and grain boundaries can strongly scatter phonons to depress lattice thermal conductivity (κlat), resulting in a low κlat of ~ 0.53 Wm− 1K− 1 and thermal conductivity (κtot) of ~ 0.62 Wm− 1K− 1 at 673 K for the Cu3Sb0.98Bi0.02Se4 sample. As a consequence, a maximum ZT value ~ 0.95 at 673 K is obtained for the Cu3Sb0.985Bi0.015Se4 sample, which is ~ 1.9 times more than that of pristine Cu3SbSe4. This work shows that isovalent heavy-element doping is an effective strategy to optimize thermoelectric properties of copper-based chalcogenides.

2012 ◽  
Vol 512-515 ◽  
pp. 1651-1654 ◽  
Author(s):  
Yu Kun Xiao ◽  
Zhi Xiang Li ◽  
Jun Jiang ◽  
Sheng Hui Yang ◽  
Ting Zhang ◽  
...  

P-type BiSbTe/RuO2 composite was fabricated using a combined process of melting and spark plasma sintering. The XRD patterns showed that RuO2 reacted with the matrix for the RuO2 content of 1.0 wt% and 4.0 wt% samples. The measured thermoelectric properties showed that the highest electrical conductivity was obtained for the sample with 2.0 wt% RuO2. The power factor (α2σ/κ) decreased with the increase of RuO2 below 450 K. The lattice thermal conductivity was lower than that of BiSbTe over the whole temperature range for BiSbTe/2.0 wt% RuO2.


2018 ◽  
Vol 773 ◽  
pp. 145-151
Author(s):  
Min Soo Park ◽  
Gook Hyun Ha ◽  
Hye Young Koo ◽  
Yong Ho Park

The Bi–Te thermoelectric system shows an excellent figure of merit (ZT) near room temperature. Research on increasing the ZT value for n‑type Bi–Te is imperative because the thermoelectric properties of this compound are inferior to those of the p-type material. For this purpose, n-type Bi2Te3-ySey powders with various amounts of Se dopant (0.3 ≤ y ≤ 0.6) were synthesized by a vacuum melting-grinding process to improve the physical properties. The ZT value of the sintered bodies was investigated in the temperature range of 298–423 K with regard to the electrical and thermal characteristics. As the Se content increased, the electrical conductivity decreased owing to a reduction in the carrier concentration, which improved the overall value of ZT. The thermal conductivity clearly decreased as the Se content increased in the temperature range of 298–373 K due to increased alloy scattering, as well as a reduction in the lattice thermal conductivity caused by crystal grain boundary scattering. At room temperature, Bi2Te2.7Se0.3 (y = 0.3) exhibited the highest ZT of 0.85. At increased temperatures, the ZT value was highest for Bi2Te2.55Se0.45 (y = 0.45), indicating that the optimal effect of the Se dopants varies depending on the temperature range.


2014 ◽  
Vol 616 ◽  
pp. 174-177
Author(s):  
Mei Jun Yang ◽  
Qiang Shen ◽  
Lian Meng Zhang

The single phase of Bi-doped Mg2Si0.3Sn0.7compounds have been successfully fabricated by solid state reaction and spark plasma sintering (SPS). The effect of Bi doping concentration on the thermoelectric properties of Mg2Si0.3Sn0.7is investigated. The doping of Bi atom results in the increase of carrier concentrations and ensures the increase of electrical conductivity. Although the thermal conductivity and Seebeck coefficient shows a slight increase, the figure of merit of Mg2Si0.3Sn0.7compounds still increases with the increasing contents of Bi-doping. When Bi-doping content is 1.5at%, the Mg2Si0.3Sn0.7compound obtained the maximum value,ZT, is 1.03 at 640 K.


Author(s):  
А.И. Таранова ◽  
А.П. Новицкий ◽  
А.И. Воронин ◽  
С.В. Таскаев ◽  
В.В. Ховайло

In this work the results of an experimental study of Fe2Ti1-xVxSn alloys (x = 0; 0.06; 0.15; 0.2) are presented. According to the temperature dependencies of the electrical conductivity, Seebeck coefficient and thermal conductivity, it is established, that the studied compositions exhibit transport properties typical for semiconductors. The substitution of V at the Ti site leads to a change of the p-type electrical conductivity behavior to n-type; the pristine sample of Fe2TiSn has the best thermoelectric properties.


2015 ◽  
Vol 44 (3) ◽  
pp. 1046-1051 ◽  
Author(s):  
Songting Cai ◽  
Zihang Liu ◽  
Jianyong Sun ◽  
Rui Li ◽  
Weidong Fei ◽  
...  

Na substituting Sb in the AgSbSe2 not only improves the power factor caused by the enhanced carrier concentration, but also decreases the thermal conductivity due to point defects, nanoscale stacking faults and Na-rich precipitate. Consequently, a high ZT value of 0.92 is achieved in the AgSb0.99Na0.01Se2 sample.


2013 ◽  
Vol 06 (05) ◽  
pp. 1340006 ◽  
Author(s):  
JINGSHU XU ◽  
CHENGUANG FU ◽  
JIAN XIE ◽  
XINBING ZHAO ◽  
TIEJUN ZHU

The p-type skutterudite compounds of ( Pr 0.25 Nd 0.75)x Fe 3 CoSb 12 (x = 0.67–0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr 0.25 Nd 0.75. The maximum ZT value of ~ 0.83 for ( Pr 0.25 Nd 0.75)0.76 Fe 3 CoSb 12 was obtained at 700 K.


1991 ◽  
Vol 234 ◽  
Author(s):  
T. L. Aselage

ABSTRACTBoron carbides are refractory solids with potential for application as very high temperature p-type thermoelectrics in power conversion applications. The thermoelectric properties of boron carbides are unconventional. In particular, the electrical conductivity is consistent with the thermally activated hopping of a high density (≈ 1021/cm3) of bipolarons; the Seebeck coefficient is anomalously large and increases with increasing temperature; and the thermal conductivity is surprisingly low. In this paper, these unusual properties and their relationship to the unusual structure and bonding present in boron carbides are reviewed. Finally, the potential for utilization of boron carbides at very high temperatures (up to 2200°C) and for preparing n-type materials is discussed.


2005 ◽  
Vol 886 ◽  
Author(s):  
Takao Mori

ABSTRACTNovel rare earth boron icosahedral compounds are investigated as potential high temperature thermoelectric materials. REB50-type compounds and a homologous series of RE-B-C(N) compounds were synthesized and the thermal conductivity and thermoelectric properties measured. Seebeck coefficients in excess of 200 μV/K are observed at temperatures above 1000 K for the REB50-type compounds. Strikingly, n-type behavior was observed for REB22C2N and REB17CN. Up to now, non-doped B12 icosahedral compounds like boron carbide have all been p-type. The discovery of an n-type compound is extremely important in terms of the potential development of this class of compounds as viable thermoelectric materials. Low thermal conductivities of κ < 0.03 W/cm/K at room temperature was observed for these rare earth boron cluster compounds. In comparison among the homologous series in which there are rare earth and B6 octahedra layers separated by an increasing number of B12 icosahedra layers, we observe that the thermal conductivity actually increases as the number of boron cluster layers increases. We find that the rare earth B12 icosahedral cluster compounds in which RE atoms occupy voids among the clusters generally appear to have lower thermal conductivity than boron cluster compounds which do not contain RE atoms.


2005 ◽  
Vol 886 ◽  
Author(s):  
Ken Kurisaki ◽  
Keita Goto ◽  
Atsuko Kosuga ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka

ABSTRACTPolycrystalline-sintered samples of thallium based substances, (Tl2Te)100−x(Sb2Te3)x (x= 0, 1, 5, 10), were prepared by melting Tl2Te and Sb2Te3 ingots followed by annealing in sealed quartz ampoules. The thermoelectric properties were measured from room temperature to around 600 K. The values of the Seebeck coefficient of all samples are positive, indicating a p-type conduction characteristic. The maximum value of the power factor is 6.53×10−4 Wm−1K−2 at 591 K obtained for x= 10 (Tl9SbTe6), which is about one order lower than those of state-of-the-art thermoelectric materials. All samples indicate an extremely low thermal conductivity, for example that of Tl2Te is approximately 0.35 Wm−1K−1 from room temperature to around 600 K. Although the electrical performance of the samples is not so good, the ZT value is relatively high due to the extremely low thermal conductivity. The maximum ZT value is 0.42 at 591 K obtained for Tl9SbTe6.


2017 ◽  
Vol 19 (36) ◽  
pp. 24928-24933 ◽  
Author(s):  
Prabhjot Kaur ◽  
Chandan Bera

A fundamental understanding of the rational design of “Pb” and “Te” free metal chalcogenide alloys, based on the abundant materials CoAsxSb(1−x)S, for both p-type and n-type highly efficient thermoelectric materials is explored.


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