Enhanced Thermoelectric Performance of Cu2Se via Nanostructure and Compositional Gradient.

Lin Bo,Degang Zhao,Yangbo Hou,Min Zuo,Fujin Li

doi:10.3390/nano12040640

Abstract

Forming co-alloying solid solutions has long been considered as an effective strategy for improving thermoelectric performance. Herein, the dense Cu2−x(MnFeNi)xSe (x = 0–0.09) with intrinsically low thermal conductivity was prepared by a melting-ball milling-hot pressing process. The influences of nanostructure and compositional gradient on the microstructure and thermoelectric properties of Cu2Se were evaluated. It was found that the thermal conductivity decreased from 1.54 Wm−1K−1 to 0.64 Wm−1K−1 at 300 K via the phonon scattering mechanisms caused by atomic disorder and nano defects. The maximum zT value for the Cu1.91(MnFeNi)0.09Se sample was 1.08 at 750 K, which was about 27% higher than that of a pristine sample.

Highlights

Thermoelectric (TE) technology can convert useless heat into electrical energy, which provides an efficient alternative route for waste heat recycling and refrigeration [1,2,3]
The Cu2−x (MnFeNi)x Se (x = 0–0.09) materials prepared by vacuum melting and rapidly hot-pressing sintering (RHP)
The results showed that the α-Cu2 Se phase was the major phase at room temperature, which was consistent with another report [39]

Summary

Introduction

Thermoelectric (TE) technology can convert useless heat into electrical energy, which provides an efficient alternative route for waste heat recycling and refrigeration [1,2,3]. TE material has attracted great attention due to its long working life and high temperature reliability. Κ where α, σ, α2 σ, κ and T are Seebeck coefficient, electrical conductivity, power factor, thermal conductivity and absolute temperature, respectively [4,5]. To optimize the zT value, band convergence [6,7,8], carrier concentration optimization [9,10], nanostructure [11], as well as interfacial engineering [12,13,14] are designed to simultaneously optimize electrical conductivity and lattice thermal conductivity. The interfacial engineering concept has been extensively used in many TE systems, such as nanocrystalline BiSbTe [16], ZrNiSn [20], SiGe [21], and PbTe [22]

Objectives

Methods

Results

Conclusion