High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template

Nan Chen, Michael R. Scimeca, Shlok J. Paul, Shihab B. Hafiz, Ze Yang, Xiangyu Liu, Fan Yang, Dong Kyun Ko, Ayaskanta Sahu

Research output: Contribution to journalArticle

Abstract

Over the past decade, Ag2Se has attracted increasing attention due to its potentially excellent thermoelectric (TE) performance as an n-type semiconductor. It has been considered a promising alternative to Bi-Te alloys and other commonly used yet toxic and/or expensive TE materials. To optimize the TE performance of Ag2Se, recent research has focused on fabricating nanosized Ag2Se. However, synthesizing Ag2Se nanoparticles involves energy-intensive and time-consuming techniques with poor yield of final product. In this work, we report a low-cost, solution-processed approach that enables the formation of Ag2Se thin films from Cu2-xSe template films via cation exchange at room temperature. Our simple two-step method involves fabricating Cu2-xSe thin films by the thiol-amine dissolution of bulk Cu2Se, followed by soaking Cu2-xSe films in AgNO3 solution and annealing to form Ag2Se. We report an average power factor (PF) of 617 ± 82 μW m-1 K-2 and a corresponding ZT value of 0.35 at room temperature. We obtained a maximum PF of 825 μW m-1 K-2 and a ZT value of 0.46 at room temperature for our best-performing Ag2Se thin-film after soaking for 5 minutes. These high PFs have been achieved via full solution processing without hot-pressing.

Original languageEnglish (US)
Pages (from-to)368-376
Number of pages9
JournalNanoscale Advances
Volume2
Issue number1
DOIs
StatePublished - Jan 1 2020

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ASJC Scopus subject areas

  • Engineering(all)
  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Chemistry(all)

Cite this

Chen, N., Scimeca, M. R., Paul, S. J., Hafiz, S. B., Yang, Z., Liu, X., Yang, F., Ko, D. K., & Sahu, A. (2020). High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template. Nanoscale Advances, 2(1), 368-376. https://doi.org/10.1039/c9na00605b