Thermoelectric Properties of Low Te Concentration‐Doped Cu₂ZnSnSe₄‐Based Quaternary Alloys

Abstract

Quaternary Cu2ZnSnSe4 alloys have attracted more attentions as promising thermoelectric materials due to their instinct low thermal conductivity. Herein, Cu2ZnSnSe4 and Cu2ZnSn0.98Pb0.02Se4−xTex (x = 0.005, 0.010, 0.015, 0.020, 0.025, 0.030) alloys are successfully synthesized by melting, annealing, and hot pressing. All samples show main kesterite structure with slight Cu0.656Te0.344 impurity phases, high relative densities, and homogeneous element distribution. A higher power factor of 678.3 μW K−2m−1 is achieved at 673 K for Cu2ZnSn0.98Pb0.02Se3.975Te0.025 alloy, which is due to the reduction of the electrical resistivity. Meanwhile, the lattice thermal conductivity is slightly increased because the lattice structure is more symmetrical with Te‐doped samples. Combining the increased point defects, the minimum lattice thermal conductivity of 1.5 Wm−1 K−1 is achieved at 673 K. As the comprehensive result, the maximum figure of merit zT of 0.24 has been obtained at 673 K for Cu2ZnSn0.98Pb0.02Se3.975Te0.025 alloy, which is about 24% higher than that of the Cu2ZnSnSe4.

Thermoelectric and Photovoltaic Properties of Mn-Doped Kesterite Cu2Zn1–xMnxSnSe4

“…At higher Mn concentrations, the larger phonon scattering due to a greater number of point defects would dominate, leading to the observed decrease in thermal conductivity. 54 Graphs of thermal diffusivities (Figure S8) and electronic thermal conductivities (Figure S9) are provided in the Supporting Information.…”

Improved Thermoelectric Performance of In‐Doped Quaternary Cu2MnSnSe4 Alloys

“…based compounds are now gaining traction in the quest to make cheaper, less-toxic, and high-efficiency thermoelectric materials due to their low thermal conductivity attributed to their complex structure. [26][27][28][29][30][31] However, their relatively low electrical transport properties are the bottle neck in their wide application for energy generation. Recently, a diamond-like compound Cu 2 MnSnSe 4 was discovered as potential thermoelectric material through pseudocubic structure approach guided by the unity-η rule.…”

Effect of annealing temperature on microstructure and thermoelectric transport properties of Cu2.1Zn0.9SnSe4 alloys

“…Cu 2 ZnSnSe 4 (CZTSe) compounds have been exclusively known for their wide applications in thin-film solar cells with certified solar conversion efficiencies around 12% due to their electronic structure and optical response [1]. Recently Cu 2 ZnSnSe 4 -based quaternary chalcogenide compounds have drawn significant interest as potential candidate for thermoelectric materials due to its intrinsically low thermal conductivity which is featured by its complex crystal structure [2][3][4][5]. In last decade, thermoelectric properties of CZTSe compounds have been extensively explored and various strategies have been employed to enhance the thermoelectric performance of CZTSe compounds, e.g.…”