Temperature- and roughness- dependent permittivity of annealed/unannealed gold films

Po Ting Shen, Yonatan Sivan, Cheng Wei Lin, Hsiang Lin Liu, Chih Wei Chang, Shi Wei Chu

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Intrinsic absorption and subsequent heat generation have long been issues for metal-based plasmonics. Recently, thermo-plasmonics, which takes the advantage of such a thermal effect, is emerging as an important branch of plasmonics. However, although significant temperature increase is involved, characterization of metal permittivity at different temperatures and corresponding thermo-derivative are lacking. Here we measure gold permittivity from 300K to 570K, which the latter is enough for gold annealing. More than one order difference in thermo-derivative is revealed between annealed and unannealed films, resulting in a large variation of plasmonic properties. In addition, an unusual increase of imaginary permittivity after annealing is found. Both these effects can be attributed to the increased surface roughness incurred by annealing. Our results are valuable for characterizing extensively used unannealed nanoparticles, or annealed nanostructures, as building blocks in future thermo-nano-plasmonic systems.

Original languageEnglish
Pages (from-to)19254-19263
Number of pages10
JournalOptics Express
Volume24
Issue number17
DOIs
Publication statusPublished - 2016 Aug 22

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ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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