Light trapping for solar fuel generation with Mie resonances

Soo Jin Kim, Isabell Thomann, Junghyun Park, Ju Hyung Kang, Alok P. Vasudev, Mark L. Brongersma

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

The implementation of solar fuel generation as a clean, terawatt-scale energy source is critically dependent on the development of high-performance, inexpensive photocatalysts. Many candidate materials, including for example α-Fe2O3 (hematite), suffer from very poor charge transport with minority carrier diffusion lengths that are significantly shorter (nanometer scale) than the absorption depth of light (micrometer scale near the band edge). As a result, most of the photoexcited carriers recombine rather than participate in water-splitting reactions. For this reason, there is a tremendous opportunity for photon management. Plasmon-resonant nanostructures have been employed to effectively enhance light absorption in the near-surface region of photocatalysts, but this approach suffers from intrinsic optical losses in the metal. Here, we circumvent this issue by driving optical resonances in the active photocatalyst material itself. We illustrate that judiciously nanopatterned photocatalysts support optical Mie and guided resonances capable of substantially enhancing the photocarrier generation rate within 10-20 nm from the water/photocatalyst interface.

Original languageEnglish
Pages (from-to)1446-1452
Number of pages7
JournalNano Letters
Volume14
Issue number3
DOIs
Publication statusPublished - 2014 Mar 12

Keywords

  • Light trapping
  • Mie resonance
  • iron oxide
  • photoelectrochemistry
  • solar fuel generation
  • water splitting

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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  • Cite this

    Kim, S. J., Thomann, I., Park, J., Kang, J. H., Vasudev, A. P., & Brongersma, M. L. (2014). Light trapping for solar fuel generation with Mie resonances. Nano Letters, 14(3), 1446-1452. https://doi.org/10.1021/nl404575e