Dipolar ligands tune plasmonic properties of tin-doped indium oxide nanocrystals

05 June 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Surface functionalization with dipolar molecules is known to tune electronic band alignment in semiconductor films and colloidal quantum dots. Yet, the influence of sur- face modification on plasmonic nanocrystals and their properties remains little explored. Here, we functionalize tin-doped indium oxide nanocrystals (ITO NCs) via ligand ex- change with a series of cinnamic acids with different electron withdrawing and donat- ing dipolar characters. Consistent with previous reports on planar and nanocrystalline semiconductors, we find that withdrawing (donating) ligands increase (decrease) the work function, which we ascribe to an electrostatic potential shift across the molecular layer. Quantitative analyses of the plasmonic extinction spectra reveal that varying the ligand molecular dipole affects the near-surface depletion layer, with an anticorrelated trend between electron concentration and electronic volume fraction, factors that are positively correlated in as-synthesized NCs. Electronic structure engineering through surface modification provides access to distinctive combinations of plasmonic prop- erties that could enable optoelectronic applications, sensing, and hot electron-driven processes.


localized surface plasmon resonance
ligand exchange
band bending
ultraviolet photoemission spectroscopy

Supplementary materials

Supplementary Information
Details of ITO NC synthesis, surface modification procedure, and characterization techniques used (STEM, NMR, TGA, UPS, optical spectroscopy, ICP-MS, and HEDA model) for all samples, plus supporting characterization data.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.