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Electronically doped metal oxide nanocrystals exhibit tunable infrared localized surface plasmon resonances (LSPRs). Despite the many benefits of IR resonant LSPRs in solution processable nanocrystals, the ways in which the electronic structure of the host semiconductor material impact metal oxide LSPRs are still being investigated. Semiconductors provide an alternative dielectric environment than metallically bonded solids, such as noble metals, which can impact how these materials undergo electronic relaxation following photoexcitation. Understanding these differences is key to developing applications that take advantage of the unique optical and electronic properties offered by plasmonic metal oxide NCs. Here, we use the two-temperature model in conjunction with femtosecond transient absorption experiments to describe how the internal temperature of two representative metal oxide nanocrystal systems, cubic WO 3−x and bixbyite Sn-doped In 2 O 3 , change following LSPR excitation. We find that the low free carrier concentrations of metal oxide NCs lead to less efficient heat generation as compared to metallic nanocrystals such as Ag. This suggests that metal oxide NCs may be ideal for applications wherein untoward heat generation may disrupt the application's overall performance, such as solar energy conversion and photonic gating.
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Tunable optical response of plasmonic metal oxide nanocrystals
AbstractThis article is based on the MRS Medal presentation given by Delia J. Milliron at the 2023 MRS Fall Meeting & Exhibit in Boston, Mass. Milliron is cited “for the development of optically tunable metal oxide nanomaterials for applications such as energy-saving electrochromic windows.”Doped metal oxide nanocrystals (NCs) provide a highly tunable platform for localized surface plasmon resonance (LSPR) in the near- to mid-IR. This tunability can be achieved synthetically, through the size, shape, and composition of the NCs, or post-synthetically through reversible redox reactions, enabling a host of emerging applications. While the broad strokes of this tunability have been understood for a decade, over the last few years, there has been tremendous progress in understanding the relationships between the electronic structure, defect chemistry, and synthetic and post-synthetic tunability of metal oxide NCs. This article aims to provide an up-to-date picture of the optical tunability of metal oxide NC LSPR, in particular focusing on recent insights into how the NC electronic structure plays a role in LSPR tunability. Graphical abstract
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- Award ID(s):
- 2303296
- PAR ID:
- 10545909
- Publisher / Repository:
- Cambridge University Press (CUP)
- Date Published:
- Journal Name:
- MRS Bulletin
- Volume:
- 49
- Issue:
- 10
- ISSN:
- 0883-7694
- Format(s):
- Medium: X Size: p. 1032-1044
- Size(s):
- p. 1032-1044
- Sponsoring Org:
- National Science Foundation
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