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Thermoelectric Performance Of Single-Phase Tellurium-Reduced Quaternary (Pbte)0.55(Pbs)0.1(Pbse)0.35, Laaya Shaabani, Graeme Blake, Andrew Manettas, Shokat Keshavarzi, Sima Aminorroaya-Yamini
Thermoelectric Performance Of Single-Phase Tellurium-Reduced Quaternary (Pbte)0.55(Pbs)0.1(Pbse)0.35, Laaya Shaabani, Graeme Blake, Andrew Manettas, Shokat Keshavarzi, Sima Aminorroaya-Yamini
Australian Institute for Innovative Materials - Papers
Lead chalcogenide quaternary systems have been shown to provide high thermoelectric (TE) efficiency superior to those of binary andternary lead chalcogenides, arising from both altered electronic band structures and a reduction in lattice thermal conductivity. Here, we have synthesized single-phase samples of the quaternary compound (PbTe)0.55(PbS)0.1(PbSe)0.35 dopedwith Na and characterized their TE properties. We show that the dopant solubility is limited to 1 at. %. A very low lattice thermal conductivity of∼0.6 Wm−1K−1at 850 K is achieved at all dopant concentrations because of phonon scattering from point defects associated with solute atoms with high contrastatomic mass. As a result, a …
Ag-Mg Antisite Defect Induced High Thermoelectric Performance Of Α-Mgagsb, Zhenzhen Feng, Jihua Zhang, Yuli Yan, Guangbiao Zhang, Chao Wang, Chengxiao Peng, Fengzhu Ren, Yuan Xu Wang, Zhenxiang Cheng
Ag-Mg Antisite Defect Induced High Thermoelectric Performance Of Α-Mgagsb, Zhenzhen Feng, Jihua Zhang, Yuli Yan, Guangbiao Zhang, Chao Wang, Chengxiao Peng, Fengzhu Ren, Yuan Xu Wang, Zhenxiang Cheng
Australian Institute for Innovative Materials - Papers
Engineering atomic-scale native point defects has become an attractive strategy to improve the performance of thermoelectric materials. Here, we theoretically predict that Ag-Mg antisite defects as shallow acceptors can be more stable than other intrinsic defects under Mg-poor-Ag/Sb-rich conditions. Under more Mg-rich conditions, Ag vacancy dominates the intrinsic defects. The p-type conduction behavior of experimentally synthesized ¿-MgAgSb mainly comes from Ag vacancies and Ag antisites (Ag on Mg sites), which act as shallow acceptors. Ag-Mg antisite defects significantly increase the thermoelectric performance of ¿-MgAgSb by increasing the number of band valleys near the Fermi level. For Li-doped ¿-MgAgSb, under more …
Improvement Of Thermoelectric Properties And Their Correlations With Electron Effective Mass In Cu1.98sxse1−X, Lanling Zhao, Frank Yun Fei, Jun Wang, Funing Wang, Chunlei Wang, Jichao Li, Ji-Yang Wang, Zhenxiang Cheng, Shi Xue Dou, Xiaolin Wang
Improvement Of Thermoelectric Properties And Their Correlations With Electron Effective Mass In Cu1.98sxse1−X, Lanling Zhao, Frank Yun Fei, Jun Wang, Funing Wang, Chunlei Wang, Jichao Li, Ji-Yang Wang, Zhenxiang Cheng, Shi Xue Dou, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
Sulphur doping effects on the crystal structures, thermoelectric properties, density-of-states, and effective mass in Cu1.98SxSe1−x were studied based on the electrical and thermal transport property measurements, and first-principles calculations. The X-ray diffraction patterns and Rietveld refinements indicate that room temperature Cu1.98SxSe1−x (x=0, 0.02, 0.08, 0.16) and Cu1.98SxSe1−x (x=0.8, 0.9, 1.0) have the same crystal structure as monoclinic-Cu2Se and orthorhombic-Cu2S, respectively. Sulphur doping can greatly enhance zT values when x is in the range of 0.8≤x≤1.0. Furthermore, all doped samples show stable thermoelectric compatibility factors over a broad temperature range from 700 to 1000K, which could greatly benefit their practical applications. …
Elemental Distributions Within Multiphase Quaternary Pb Chalcogenide Thermoelectric Materials Determined Through Three-Dimensional Atom Probe Tomography, Sima Aminorroaya-Yamini, Tong Li, David R. G Mitchell, Julie M. Cairney
Elemental Distributions Within Multiphase Quaternary Pb Chalcogenide Thermoelectric Materials Determined Through Three-Dimensional Atom Probe Tomography, Sima Aminorroaya-Yamini, Tong Li, David R. G Mitchell, Julie M. Cairney
Australian Institute for Innovative Materials - Papers
Nanostructured multiphase p-type lead chalcogenides have shown the highest efficiencies amongst thermoelectric materials. However, their electronic transport properties have been described assuming homogenous distribution of dopants between phases. Here, we have analyzed elemental distributions in precipitates and matrices of nanostructured multiphase quaternary Pb chalcogenides doped to levels below and above the solubility limit of the matrix, using three-dimensional atom probe tomography. We demonstrate that partitioning of sodium and selenium occur between the matrix and secondary phase in both lightly- and heavily-doped compounds and that the concentrations of sodium and selenium in precipitates are higher than those in the matrices. This …
Lead-Free Snte-Based Thermoelectrics: Enhancement Of Thermoelectric Performance By Doping With Gd/Ag, Lijuan Zhang, Jian Li Wang, Zhenxiang Cheng, Qiao Sun, Zhen Li, S X. Dou
Lead-Free Snte-Based Thermoelectrics: Enhancement Of Thermoelectric Performance By Doping With Gd/Ag, Lijuan Zhang, Jian Li Wang, Zhenxiang Cheng, Qiao Sun, Zhen Li, S X. Dou
Australian Institute for Innovative Materials - Papers
SnTe, with the same rock-salt structure as PbTe, is a potentially attractive thermoelectric material. Pristine SnTe has poor thermoelectric performance because of its very high hole concentration resulting from intrinsic Sn vacancies, which leads to a high thermal conductivity and a low Seebeck coefficient. In this work, the thermoelectric properties of SnTe were modified by doping with different contents of gadolinium and silver. It is found that SnTe doped with optimal gadolinium (i.e. Gd0.06Sn0.94Te) exhibited extraordinarily low lattice thermal conductivity that is close to the theoretical minimum. The drastic reduction of lattice thermal conductivity is attributed to the formation of …
One-Step Bonding Of Ni Electrode To N-Type Pbte - A Step Towards Fabrication Of Thermoelectric Generators, Xavier Reales Ferreres, Sima Aminorroaya-Yamini, Mitchell John Bromley Nancarrow, C Zhang
One-Step Bonding Of Ni Electrode To N-Type Pbte - A Step Towards Fabrication Of Thermoelectric Generators, Xavier Reales Ferreres, Sima Aminorroaya-Yamini, Mitchell John Bromley Nancarrow, C Zhang
Australian Institute for Innovative Materials - Papers
PbTe-based thermoelectric materials are good candidates for harvesting waste heat at mid-range temperatures due to their high thermoelectric efficiencies. Excellent quality and reliability of the bonding between the thermoelectric material and the electrode at high temperatures are essential for manufacturing thermoelectric generators. Here, a technique has been developed to achieve high-quality bonding between PbTe and the electrode. We have successfully performed one-step sintering of nickel electrode to n-type PbTe powder using spark plasma sintering. The fabricated interphase, composed of nickel telluride, is continuous and homogeneous across the junction, without visible flaws on the electrode or in the interphase and PbTe. …
Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou
Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou
Australian Institute for Innovative Materials - Papers
A robust low-cost ambient aqueous method for the scalable synthesis of surfactant-free nanostructured metal chalcogenides (MaXb, M=Cu, Ag, Sn, Pb, and Bi; X=S, Se, and Te; a=1 or 2; and b=1 or 3) is developed in this work. The effects of reaction parameters, such as precursor concentration, ratio of precursors, and amount of reducing agent, on the composition, size, and shape of the resultant nanostructures have been comprehensively investigated. This environmentally friendly approach is capable of producing metal chalcogenide nanostructures in a one-pot reaction on a large scale, which were investigated for their thermoelectric properties towards conversion of waste heat …
Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu
Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu
Australian Institute for Innovative Materials - Papers
Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can …
Fabrication Of Thermoelectric Materials-Thermal Stability And Repeatability Of Achieved Efficiencies, Sima Aminorroaya-Yamini, Matthew D. Brewis, Jacob Byrnes, Rafael Santos, Andrew Manettas, Y Z. Pei
Fabrication Of Thermoelectric Materials-Thermal Stability And Repeatability Of Achieved Efficiencies, Sima Aminorroaya-Yamini, Matthew D. Brewis, Jacob Byrnes, Rafael Santos, Andrew Manettas, Y Z. Pei
Australian Institute for Innovative Materials - Papers
Metal chalcogenides have delivered the highest efficiencies among thermoelectric materials. Although the thermal stability of thermoelectric materials at device operating temperatures has been of concern, recent studies have reported the efficiencies of materials prepared with different fabrication techniques. Here, we have fabricated a p-type, multiphase lead chalcogenide compound of (PbTe)0.55(PbS)0.35(PbSe)0.1, with three common fabrication techniques of quenched, quenched-annealed and furnace cooled followed by spark plasma sintering. The compound contains PbS-rich precipitates within a PbTe-rich matrix. The achieved samples from various fabrication procedures demonstrate distinct microstructures that evolve with thermal cycling. We have shown that the thermoelectric efficiency of metastable compound …
Recent Progress In Thermoelectric Materials, Chao Han, Zhen Li, S X. Dou
Recent Progress In Thermoelectric Materials, Chao Han, Zhen Li, S X. Dou
Australian Institute for Innovative Materials - Papers
Direct conversion of heat into electricity through advanced thermoelectric (TE) materials has been one of the most attractive solutions to the severe environmental and energy issues facing humanity. In recent years, great progress has been made in improving their dimensionless figure of merit (ZT), which determines the conversion efficiency of TE devices. ZT is related to three “interlocked” factors—the Seebeck coefficient, electrical conductivity, and thermal conductivity. These three factors are interdependent in bulk TE materials, and altering one changes the other two. The difficulty in simultaneously optimizing them caused TE research to stagnate, until great reductions in thermal conductivity were …
Thermoelectric Performance Of N-Type (Pbte)0.75(Pbs)0.15(Pbse)0.1 Composites, Sima Aminorroaya Yamini, Heng Wang, Dianta Ginting, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Thermoelectric Performance Of N-Type (Pbte)0.75(Pbs)0.15(Pbse)0.1 Composites, Sima Aminorroaya Yamini, Heng Wang, Dianta Ginting, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Australian Institute for Innovative Materials - Papers
Lead chalcogenides (PbQ, Q = Te, Se, S) have proved to possess high thermoelectric efficiency for both n-type and p-type compounds. Recent success in tuning of electronic band structure, including manipulating the band gap, multiple bands, or introducing resonant states, has led to a significant improvement in the thermoelectric performance of p-type lead chalcogenides compared to the n-type ones. Here, the n-type quaternary composites of (PbTe)0.75(PbS)0.15(PbSe)0.1 are studied to evaluate the effects of nanostructuring on lattice thermal conductivity, carrier mobility, and effective mass variation. The results are compared with the similar ternary systems of (PbTe)1-x(PbSe)x, (PbSe) 1-x(PbS)x, and (PbS)1-x(PbTe)x. The …
Thermoelectric Performance Of Tellurium-Reduced Quaternary P-Type Lead-Chalcogenide Composites, Sima Aminorroaya Yamini, Heng Wang, Zachary M. Gibbs, Yanzhong Pei, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Thermoelectric Performance Of Tellurium-Reduced Quaternary P-Type Lead-Chalcogenide Composites, Sima Aminorroaya Yamini, Heng Wang, Zachary M. Gibbs, Yanzhong Pei, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Australian Institute for Innovative Materials - Papers
A long-standing technological challenge to the widespread application of thermoelectric generators is obtaining high-performance thermoelectric materials from abundant elements. Intensive study on PbTe alloys has resulted in a high figure of merit for the single-phase ternary PbTe-PbSe system through band structure engineering, and the low thermal conductivity achieved due to nanostructuring leads to high thermoelectric performance for ternary PbTe-PbS compounds. Recently, the single-phase p-type quaternary PbTe-PbSe-PbS alloys have been shown to provide thermoelectric performance superior to the binary and ternary lead chalcogenides. This occurs via tuning of the band structure and from an extraordinary low thermal conductivity resulting from high-contrast …
Ambient Scalable Synthesis Of Surfactant-Free Thermoelectric Cuagse Nanoparticles With Reversible Metallic-N-P Conductivity Transition, Chao Han, Qiao Sun, Zhenxiang Cheng, Jianli Wang, Zhen Li, Gao Qing (Max) Lu, S X. Dou
Ambient Scalable Synthesis Of Surfactant-Free Thermoelectric Cuagse Nanoparticles With Reversible Metallic-N-P Conductivity Transition, Chao Han, Qiao Sun, Zhenxiang Cheng, Jianli Wang, Zhen Li, Gao Qing (Max) Lu, S X. Dou
Australian Institute for Innovative Materials - Papers
Surfactant-free CuAgSe nanoparticles were successfully synthesized on a large scale within a short reaction time via a simple environmentally friendly aqueous approach under room temperature. The nanopowders obtained were consolidated into pellets for investigation of their thermoelectric properties between 3 and 623 K. The pellets show strong metallic characteristics below 60 K and turn into an n-type semiconductor with increasing temperature, accompanied by changes in the crystal structure (i.e., from the pure tetragonal phase into a mixture of tetragonal and orthorhombic phases), the electrical conductivity, the Seebeck coefficient, and the thermal conductivity, which leads to a figure of merit (ZT) …
Thermoelectric Properties Of Ca3co4o9 And Ca2.8bi0.2co4o9 Thin Films In Their Island Formation Mode, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Thermoelectric Properties Of Ca3co4o9 And Ca2.8bi0.2co4o9 Thin Films In Their Island Formation Mode, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Australian Institute for Innovative Materials - Papers
Ca3Co4O9 and Ca2.8Bi 0.2Co4O9 thin films were fabricated on LaAlO3 (LAO) substrate using pulsed laser deposition technique and were studied for their thermoelectric (TE) properties in Stranski-Krastanov mode for the first time. The thin films consisted of 3D clusters/islands on a 14-nm thick 2D layer with cluster density being higher for Ca 2.8Bi0.2Co4O9 thin films. The clusters also represent areas of dislocation and therefore act as carrier scattering centers, which leads to a temperature-activated type conductivity. Seebeck coefficient as high as 136 and 163 u V/K was measured for the Ca 3Co4O9 and Ca2.8Bi 0.2Co4O9 thin films, respectively, which is …
Rational Design Of P-Type Thermoelectric Pbte: Temperature Dependent Sodium Solubility, Sima Aminorroaya-Yamini, Teruyuki Ikeda, Aaron Lalonde, Yanzhong Pei, S X. Dou, G. Jeffrey Snyder
Rational Design Of P-Type Thermoelectric Pbte: Temperature Dependent Sodium Solubility, Sima Aminorroaya-Yamini, Teruyuki Ikeda, Aaron Lalonde, Yanzhong Pei, S X. Dou, G. Jeffrey Snyder
Australian Institute for Innovative Materials - Papers
We develop a solid understanding of the termperature-dependent solubility of sodium p-type PbTe, the most efficient thermoelectric material. The maximum solubility of socium telluride (NaTe) in PbTe is measured to be 1.4+0.3 at percent and the heat of solution is evaluated and that addresses fundamental issues regarding the formation of nano-precipitates.
Phase Formation And Magnetotransport Of Alkali Metal Doped Na0.75coo2 Thermoelectric Oxide, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou, H Yamauchi, M Karppinen
Phase Formation And Magnetotransport Of Alkali Metal Doped Na0.75coo2 Thermoelectric Oxide, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou, H Yamauchi, M Karppinen
Australian Institute for Innovative Materials - Papers
Synthesis and characterization of bulk NaxCoO2 samples substituted by K and Rb is reported. Phase formation studies revealed a narrow stable region for Na-alkali metal-Co system. Whisker and platelike single crystalline structures have been found to form on the surface of the pellets in case of K doping. All samples were metallic and no characteristic anomaly in R-T curves was observed for Rb doped sample. Magnetoresistance measured has a pronounced positive response only for K-doped and pure NaxCoO2 phases, reaching 11% and 7% at 5 K temperature, respectively.
Electronic Texture Of The Thermoelectric Oxide Na0.75coo2, M -H Julien, C De Vaulx, H Mayaffre, C Berthier, M Horvatic, V Simonet, J Wooldridge, G Balakrishnan, M R. Lees, Dapeng Chen, C T. Lin, P Lejay
Electronic Texture Of The Thermoelectric Oxide Na0.75coo2, M -H Julien, C De Vaulx, H Mayaffre, C Berthier, M Horvatic, V Simonet, J Wooldridge, G Balakrishnan, M R. Lees, Dapeng Chen, C T. Lin, P Lejay
Australian Institute for Innovative Materials - Papers
From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering on the cobalt electronic states in Na0.75CoO2: at long time scales, there is neither a disproportionation into 75 % Co3+ and 25 % Co4+ states, nor a mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an intermediate configuration in which 30 % of the lattice sites form an ordered pattern of localized Co3+ states. Above 180 K, an anomalous mobility of specific Na+ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing …