Phase transition enhanced thermoelectric performance in Cu2Se
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Date
2014-02-06
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Publisher
Australian Institute of Physics
Abstract
Worldwide efforts to searching for good thermoelectric materials are frequently focusing on normal phases in crystalline semiconductors. The material’s thermoelectric performance is described the parameter of figure of merit, zT, which is around unity around room temperature and above 1.5 at high temperatures. In the Cu2Se with anti-fluorite structure above 400K, Se atoms form a rigid face-centred cubic lattice, while the copper ions are highly disordered or moving around the tetrahedral voids with liquid-like mobility, resulting in an extraordinarily low lattice thermal conductivity, which enables zT up to 1.5 at 1,000K. Here, we report significantly enhanced thermoelectric performance during the phase transitions in Cu2Se and iodine doped Cu2Se. It is showed that the critical electron and phonon scattering greatly improve the thermopower and strongly reduce the thermal coductivity, leading to the improvement in the figure of merit more than 3-7 times compared to the normal phases, and achieving zT value of 2.3 at 400K. This mechanism pave a new way to increase the figure of merit of thermoelectric materials, and expend the utility of thermoelectrics in electronic cooling industry.z
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Keywords
Chalcogenides, Copper compounds, Electrical properties, Halogens, Materials, Nonmetals, Phase transformations, Physical properties, Selenium compounds, Semiconductor materials, Thermodynamic properties, Transition element compounds
Citation
Liu, H., Shi, X., Zhang, W., Chen, L., & Danilkin, S. (2014). Phase transition enhanced thermoelectric performance in Cu2Se. Poster presented to the 38th Annual Condensed Matter and Materials Meeting 2014, Waiheke Island Resort, Waiheke, Auckland, New Zealand; 4th February - 7th February, 2014. Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2014/Wagga2014proceedings.pdf