Harvesting light energy for solar-driven applications (e.g. photocatalytic water splitting, photovoltaics, CO2 control, and environmental remediation) are currently limited by the optical absorption and loss of the material. One current approach for light-trapping involves incorporating the plasmonic properties of metals to improve the absorption in a surrounding semiconductor material. Unfortunately, metals have high optical loss in the visible-ultraviolet region and lack optical tunability. To address this problem, the family of Sr1-xNb1-yO3+δ (SNO) metal oxides has attracted interest for their plasmon-enhanced photocatalytic and low-loss response. The current project proposes investigating the plasmonic excitations in low dimensional SNO nanoparticles by leveraging the nanoparticle stoichiometry, size, and shape to tune the optical absorption. In this work, SNO nanoparticles (&lt;100 nm) were synthesized via wet chemistry techniques such as molten salt and hydrothermal chemistry. Preliminary structural and optical characterization results confirm that the conversion of niobium oxide into SNO is transport limited by the competition between the solvent cation and Sr atom. The nanoparticle size and shape can be modified by systematically controlling the precursor ratio (Sr/Nb), reaction pH, and reaction time. Additionally, the local geometry around intercalated Sr atom, probed via X-ray absorption spectroscopy and UV-vis spectroscopy, affirm that the reconstruction of the infused lattice provides enhancement in the optical absorption. Finally, X-ray photoelectron spectroscopy studies revealed that the high free electron charge density is responsible for the formation of bulk and surface plasmon modes upon exposure to visible radiation. These initial results demonstrate the existence of plasmonics in low dimensional SNO nanoparticles with tunable light absorption.

Plasmonic excitations in strained Sr1-xNb1-yO3+δ nanoparticles

255th National Meeting (2018)

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