Energy‐Efficient Synthesis and High Thermoelectric Performance of α‐Cu_2−ySe_1−xTe_x

Abstract

The high‐temperature phase of β‐Cu2Se always appears as the major phase for the reaction carried out using chemical solution methods. Here, a procedure was developed that could fabricate a single phase of α‐Cu2Se1−xTex (x=0.02 and 0.04) by room‐temperature aqueous synthesis using NaBH4 as reducing agent followed by cold pressing and sintering at 650 °C for 6 h in a flowing gas mixture of 20 % H2 and 80 % N2. The energy‐efficient synthesis carried out at room temperature abides by the 6th principle for green chemistry with less energy consumption. The reaction mechanism was studied, and evidence was provided of α‐Cu2Se being formed via the reaction between elemental Cu and Se atoms at room temperature. The resulting materials were characterized by powder X‐ray diffraction, field‐emission scanning electron microscopy, thermoelectric transport measurements, and Hall measurements. Cu1.96Se0.96Te0.04 had the highest power factor of 11 μW cm−1 K−2 at 818 K, and Cu2Se0.96Te0.04 had the maximum zT≥1.4 at T≥920 K among this series of materials.

Influence of structure phase transition on the thermoelectric properties of Cu2Se1−xTex liquid-like compounds

“…6b). 20,[31][32][33][34]39,40 In the Te contents range from x ¼ 0.2 to 0.3, we found that the transition phase point at Te of 0.25 achieved the highest ZT value, compared with other Te contents. K. Zhao et al investigated the thermoelectric © 2022 The Author(s).…”

“…6b). 20,31–34,39,40 In the Te contents range from x = 0.2 to 0.3, we found that the transition phase point at Te of 0.25 achieved the highest ZT value, compared with other Te contents. K. Zhao et al investigated the thermoelectric properties of Cu 2 Se 1− x Te x ( x = 0 to 1) solid solutions and they found the highest ZT value with x = 0.3 but the series of samples of x = 0.25 was missed.…”

“…By using the chemical method, F.-H. Lin et al reported the ZT value of 1.2 at 773 K and 1.4 at 920 K for the Cu 2 Se 0.96 Te 0.04 sample. 34 At around the transitional phase of the Cu 2 Se 1− x Te x (with Te contents between 0.2 to 0.3), the influence of Te content on the thermoelectric properties of these materials should be clarified.…”

Enhanced Thermoelectric Performance of p-Type Mg3–xZnxSb2/Sb Composites: The Role of ZnSb/Sb Composites

“…The total thermal conductivity is composed of electronic and lattice thermal conductivities, κ e and κ L , respectively. 2 For a TE material to be considered good, it should have high electrical conductivity, large thermopower, and low thermal conductivity, which are interrelated, making the optimization of parameters essential. In the past, doping, 2 alloying, 3 and band engineering 4 were used to enhance the electronic transport properties of TE materials.…”

Effect of PbS Thin Film Thickness with Cu-Doping on Thermoelectric Properties Using Spin Coating Method

“…A thermoelectric device is a technology that can directly convert heat energy into electrical energy [1], [2]. In principle, this technology uses a material that can collect thermal energy and convert it into electrical energy [1]- [4].…”