Abstract
The addition of Cu to layered Bi₂Te₃-based thermoelectric alloys has been studied as an effective way to enhance thermoelectric transport properties. In this study, the influence of adding Cu to Bi₂Se₃ alloys, which have the same rhombohedral crystal structure as Bi₂Te₃, was investigated by synthesizing a series of Cu_xBi₂Se₃ (x..... More

Abstract
Bi₂Te₃-based alloys have been extensively studied as thermoelectric materials near room temperature. In this study, the electrical, thermal, and thermoelectric transport properties of a series of Co-doped n-type Cu_0.008Bi₂Te_2.6Se_0.4 polycrystalline alloys (Cu_0.008Bi_2−xCo_xTe_2.6Se_0.4, x = 0, 0.03, 0.06, 0.09 and 0.12) are investigated. The electrical conductivity of the Cu_0.008Bi_1.97Co_0.03Te_2.6Se_0.4 (x =..... More

Abstract
YbCd₂Sb₂ is a promising Zintl compound for waste heat recovery applications due to its low thermal conductivity, originating from its complex crystal structure. Many strategies such as alloying or doping have been suggested to further reduce the thermal conductivity of YbCd₂Sb₂ to improve its thermoelectric performance. However, the..... More

Abstract
In this study, a mechanical exfoliation method was developed for the synthesis of high purity Bi₂Te₃, Sb₂Te₃, and Bi_0.5Sb_1.5Te₃ flakes. The synthesized Bi₂Te₃, Sb₂Te₃, and Bi_0.5Sb_1.5Te₃ flakes were characterized by atomic force microscope, Raman spectroscopy, and photoluminescence (PL). The effect of the thickness of the Bi₂Te₃, Sb₂Te₃, and Bi_0.5Sb_1.5Te₃ flakes..... More

Abstract
Environmentally sustainable thermoelectric technologies can be more broadly applied in industries once the performance of thermoelectric materials is improved. Several approaches have been proposed to improve the electronic transport properties of thermoelectric materials. The effects of each approach on the electronic properties can be evaluated by changes in the band..... More

Abstract
One of the most popular routes used to improve the thermoelectric performance of materials is to suppress their lattice thermal conductivities. Thermoelectric performance is characterized by a figure-of-merit zT, which is defined as σS²T/(κ_e + κ_l), where the σ, S, T, κ_e, and κ_l are the electrical conductivity, Seebeck coefficient,..... More

Abstract
We investigated the effect of Ni doping on the electrical, thermal, and thermoelectric transport properties of FeSe₂ polycrystalline alloys. FeSe₂ alloys exhibit both n-type and p-type conduction at different temperatures and thus their practicality as a thermoelectric material is somewhat limited. In this study, Fe_1-xNi_xSe₂ polycrystalline samples with x =..... More

Abstract
Re₂Te₅ is considered a potential thermoelectric material because of its intrinsically low thermal conductivity, due to its complex crystal structure. Herein, a series of Se-doped Re₂Te₅ (Re₂Te_5-xSe_x, x = 0, 0.2, 1, and 2) samples were synthesized, and their electrical and thermal transport properties were investigated. Pure orthorhombic Re₂Te₅ phases..... More

Abstract
Bi₂O₂Se oxyselenide has been actively studied as a potential n-type thermoelectric material because of its intrinsically low thermal conductivity and high Seebeck coefficient (S). However, Bi₂O₂Se has very low electrical conductivity (σ), resulting in relatively poor thermoelectric performance. Herein, we investigate the effect of Cu addition on the electrical and..... More

Abstract
In this study, we investigated the phase formation behavior of the FeSe₂-FeTe₂ system and the evolution of their thermoelectric transport properties. A series of Fe(Se_1-xTe_x)₂(x = 0, 0.2, 0.6, 0.8 and 1) compounds were synthesized by conventional solid-state reaction. Single phase orthorhombic structures were formed, except for FeSe_0.4Te_1.6(x = 0.2)...... More

Abstract
The widespread application of thermoelectric devices in cooling and waste heat recovery systems will be achieved when materials achieve high thermoelectric performance. However, improving thermoelectric performance is not straightforward because the Seebeck coefficient and electrical conductivity of the materials have opposite trends with varying carrier concentration. Here, we demonstrate that..... More

Abstract
Using thermoelectric refrigerators can address climate change because they do not utilize harmful greenhouse gases as refrigerants. To compete with current vapor compression cycle refrigerators, the thermoelectric performance of materials needs to be improved. However, improving thermoelectric performance is challenging because of the trade-off relationship between the Seebeck coefficient and..... More

Abstract
In this study, we report the influence of Te vacancy formation on the thermoelectric properties of n-type Cu_0.008Bi₂Te_2.7Se_0.3 alloys, including their electronic and thermal transport properties. Te-deficient Cu_0.008Bi₂Te_2.7-xSe_0.3 (x = 0, 0.005, 0.01 and 0.02) samples were systematically synthesized and characterized. Regarding electronic transport properties, carrier concentration was increased with..... More

Abstract
In this study, we report how Cu doping can modify the thermoelectric performance of p-type Bi_0.5Sb_1.5Te3 and Bi_0.4Sb_1.6Te3 thermoelectric alloys, including their electronic and thermal transport properties. For electronic transport, the power factors of both Bi_0.5Sb_1.5Te3 and Bi0.4Sb1.6Te3 compositions were increased by Cu doping. The origins of the enhanced power..... More

Abstract
Layered post transition metal chalcogenides such as SnSe, SnSe₂, In₂Se₃, and In₄Se₃ have attracted attention as promising thermoelectric materials due to their intrinsically low lattice thermal conductivities. Recently, n-type indium selenide (InSe) based materials have also been suggested as good candidates for thermoelectric materials by optimizing their electrical properties, i.e.,..... More

Abstract
Herein we report the effect of Cu/In doping on the electronic and thermal transport properties of Bi-Sb-Te thermoelectric alloys. To closely examine the role of each doping element when incorporated in a Bi_0.4Sb_1.6Te₃ alloy, different groups of samples were prepared and characterized, including undoped Bi_0.4Sb_1.6Te₃, In single-doped samples and In..... More