Broad temperature plateau for high ZTs in heavily doped p-type SnSe single crystals

Kunling Peng, Xu Lu, Heng Zhan, Si Hui, Xiaodan Tang, Guiwen Wang, Jiyan Dai, Ctirad Uher, Guoyu Wang, Xiaoyuan Zhou

Research output: Journal article publicationJournal articleAcademic researchpeer-review

284 Citations (Scopus)

Abstract

Excellent thermoelectric performance is obtained over a broad temperature range from 300 K to 800 K by doping single crystals of SnSe. The average value of the figure of merit ZT, of more than 1.17, is measured from 300 K to 800 K along the crystallographic b-axis of 3 at% Na-doped SnSe, with the maximum ZT reaching a value of 2 at 800 K. The room temperature value of the power factor for the same sample and in the same direction is 2.8 mW mK-2, which is an order of magnitude higher than that of the undoped crystal. Calculations show that Na doping lowers the Fermi level and increases the number of carrier pockets in SnSe, leading to a collaborative optimization of the Seebeck coefficient and the electrical conductivity. The resultant optimized carrier concentration and the increased number of carrier pockets near the Fermi level in Na-doped samples are believed to be the key factors behind the spectacular enhancement of the average ZT.
Original languageEnglish
Pages (from-to)454-460
Number of pages7
JournalEnergy and Environmental Science
Volume9
Issue number2
DOIs
Publication statusPublished - 1 Feb 2016

ASJC Scopus subject areas

  • Environmental Chemistry
  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Pollution

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