Enhancing thermoelectric performance of Cu2Se by doping Te
Yong-Bin Zhu1, Bo-Ping Zhang, Yong Liu
1The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China. bpzhang@ustb.edu.cn.
Physical Chemistry Chemical Physics : PCCP
|October 7, 2017
Summary
Adding tellurium (Te) to copper selenide (Cu2Se) enhances its thermoelectric properties. This study shows that a small Te addition significantly boosts the thermoelectric figure of merit (ZT) by improving power factor and reducing thermal conductivity.
Area of Science:
- Materials Science
- Solid State Physics
- Energy Conversion
Background:
- Copper selenide (Cu2Se) exhibits promising thermoelectric properties due to its electrical characteristics and crystal structure.
- Thermoelectric materials convert heat energy into electrical energy, crucial for waste heat recovery and solid-state cooling.
Purpose of the Study:
- To investigate the impact of tellurium (Te) substitution on the thermoelectric performance of stoichiometric copper selenide (Cu2Se).
- To optimize the thermoelectric figure of merit (ZT) in Cu2Se-based materials.
Main Methods:
- Mechanical alloying (MA) was used to synthesize a series of Cu2Se1-xTex (x = 0, 0.02, 0.04, 0.06, 0.08) bulk samples.
- Spark plasma sintering (SPS) was employed to consolidate the synthesized powders into dense bulk materials.
- Phase structure, microstructure, and thermoelectric properties (ZT, power factor, thermal conductivity) were systematically analyzed.
Main Results:
- A maximum thermoelectric figure of merit (ZT) of 1.25 was achieved for the Cu2Se0.98Te0.02 sample at 773 K.
- The enhanced ZT resulted from a significant increase in the power factor (PF) and a reduction in thermal conductivity (κ).
- Te substitution effectively modified the phase structure and microstructure, contributing to improved thermoelectric performance.
Conclusions:
- The introduction of Te into stoichiometric Cu2Se is a viable strategy to enhance its thermoelectric figure of merit (ZT).
- Optimizing Te content leads to improved power factor and reduced thermal conductivity, making these materials more efficient for thermoelectric applications.
- This research provides a convenient method for developing high-performance thermoelectric materials based on Cu2Se.
