Publication detail

From anhydrous Zinc Oxide Nanoparticle Powders to Aqueous Colloids: Impact of Water Condensation and Organic Salt Adsorption on Free Exciton Emission

KOCSIS, K. NIEDERMAIER, M. KAŠPÁREK, V. BERNARDI, J. REDHAMMER, G. BOCKSTEDTE, M. BERGER, T. DIWALD, O.

Original Title

From anhydrous Zinc Oxide Nanoparticle Powders to Aqueous Colloids: Impact of Water Condensation and Organic Salt Adsorption on Free Exciton Emission

Type

journal article in Web of Science

Language

English

Original Abstract

Variations in the composition and structure of ZnO nanoparticle interfaces have a key influence on the materials´ optoelectronic properties and are responsible for high number of discrepant results reported for ZnO-based nanomaterials. Here, we conduct a systematic study of the room-temperature photoluminescence of anhydrous ZnO nanocrystals, as synthetized in the gas phase and processed in water-free atmosphere, and of their colloidal derivatives in aqueous dispersions with varying amounts of organic salt admixtures. A free exciton band at photo-energy 3.3 eV and induces a small but significant release in lattice strain as detected by X-ray diffraction. Most importantly, admixture of acetate or citrate ions to the aqueous colloidal dispersions not only allows for the control of the zeta-potential but also affects the intensity of the free exciton emission in a correlated manner. The buildup of negative charge at solid-luquid interface, as produced by citrate adsorption, increase the free exciton emission. This effect is attributed to the suppression of electron trapping in the near-surface region, which counteracts nonradiative exciton recombination. Using well-defined ZnO nanoparticles as model systems for interface chemistry studies, our finding higlight water-induced key effects that depend on the composition of the aqueous solution shell around the semiconducting metal oxide nanoparticles.

Keywords

nanoparticle powders; water adsorption; strain release; free exciton emission; interface engineering

Authors

KOCSIS, K.; NIEDERMAIER, M.; KAŠPÁREK, V.; BERNARDI, J.; REDHAMMER, G.; BOCKSTEDTE, M.; BERGER, T.; DIWALD, O.

Released

3. 6. 2019

Publisher

American Chemical Society

Location

1155 Sixteenth Street N. W., Washington, DC 20036

ISBN

0743-7463

Periodical

Langmuir

Year of study

35

Number

26

State

United States of America

Pages from

8741

Pages to

8747

Pages count

7

URL

https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.9b00656

BibTex

@article{BUT157410,
  author="Krisztina {Kocsis} and Matthias {Niedermaier} and Vít {Kašpárek} and Johannes {Bernardi} and Günther {Redhammer} and Michel {Bockstedte} and Thomas {Berger} and Oliver {Diwald}",
  title="From anhydrous Zinc Oxide Nanoparticle Powders to Aqueous Colloids: Impact of Water Condensation and Organic Salt Adsorption on Free Exciton Emission",
  journal="Langmuir",
  year="2019",
  volume="35",
  number="26",
  pages="8741--8747",
  doi="10.1021/acs.langmuir.9b00656",
  issn="0743-7463",
  url="https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.9b00656"
}