Facile fabrication of one-dimensional Te/Cu2Te nanorod composites with improved thermoelectric power factor and low thermal conductivity

Abstract

In this study, Te/Cu2Te nanorod composites were synthesized using various properties of Cu2Te, and their thermoelectric properties were investigated. The nanorods were synthesized through a solution phase mixing process, using polyvinylpyrrolidone (PVP). With increasing Cu2Te content, the composites exhibited a reduced Seebeck coefficient and enhanced electrical conductivity. These characteristic changes were due to the high electrical conductivity and low Seebeck coefficient of Cu2Te. The composite containing 30 wt.% of Cu2Te nanorods showed the maximum power factor (524.6 μV/K at room temperature). The two types of nanorods were assembled into a 1D nanostructure, and with this structure, thermal conductivity decreased owing to the strong phonon scattering effect. This nanorod composite had a dramatically improved ZT value of 0.3, which was ~545 times larger than that of pristine Te nanorods.

Raman Spectroscopy Study of Phonon Liquid Electron Crystal in Copper Deficient Superionic Thermoelectric Cu2–xTe

“…[19][20][21][22]3,[23][24][25][26][27][28]6,29,30 Further, the superionic CT2 has an interesting structure where the tellurium atom forms a rigid sublattice and the liquid-like Cu ions are distributed randomly in the rigid sublattice and thus classified as PLEC. 31 It has been observed that several state of the art TE materials are tellurides, such as PbTe, SnTe, 32,4,5 and Bi 2 Te 3 , 14,15 and have better performances than their Se and S counterparts. 24,25,8 Thus, the present work focuses on the Raman spectroscopic studies of copper tellurides.…”

“…Like the copper selenides and the sulfides, copper tellurides (CTs) also have an interesting structure, where the tellurium atom forms a rigid sublattice and the liquid-like Cu ions are distributed randomly in the rigid sublattice and thus classified as PLEC. 31 As a member of the chalcogenide group, CT is expected to possess superior zT because of Te being a heavier element than S and Se along with less ionic bonding with Cu leading to higher carrier mobility. 8 However, for the case of CT2, the TE performance is significantly poorer than those of the Se and S counterparts because of high hole doping from Cu deficiency.…”

“…Recently, superionic Cu 2– x X (X = S, Se) are reported to have ultralow κ and high zT due to the liquid-like behavior of Cu ions around the crystalline sublattice of X and are considered as a new class of phonon–liquid–electron–crystals (PLEC). − ,,− ,,, Further, the superionic CT2 has an interesting structure where the tellurium atom forms a rigid sublattice and the liquid-like Cu ions are distributed randomly in the rigid sublattice and thus classified as PLEC . It has been observed that several state of the art TE materials are tellurides, such as PbTe, SnTe, ,, and Bi 2 Te 3 , , and have better performances than their Se and S counterparts. ,, Thus, the present work focuses on the Raman spectroscopic studies of copper tellurides.…”

Effect of SrTiO3 Nanoparticles in Conductive Polymer on the Thermoelectric Performance for Efficient Thermoelectrics

“…The efficiency of TE materials can be evaluated by the dimensionless figure of merit, ZT = S 2 •σ•T/κ, where S, σ, T, and κ are, respectively, the Seebeck coefficient, the electrical conductivity, the absolute temperature, and the total thermal conductivity. The previous studies generally focused on inorganic TE materials such as Te-based compounds (Bi 2 Te 3 , Ag 2 Te, and Cu 2 Te) [10][11][12], Se alloys (SnSe, Cu 2 Se) [13][14][15], and conducting oxides (NaCo 2 O 4 , CaMnO 3 ) [16,17]; however, these materials are typically expensive and brittle, which prevents their application in large areas. Thus, polymer-based TE materials have recently been widely used for energy harvesting due to their unique advantages, i.e., low cost, low processing temperature, and mechanical flexibility.…”

Thermoelectric Properties of Cu2SnSe3-SnS Composite

“…The total thermal conductivity can be further divided into lattice thermal conductivity (κ l ) and carrier thermal conductivity (κ e ). A good TE material should have a large σ and S with low κ [3].…”