ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
3 files

The Effect of Particle Size on the Optical and Electronic Properties of MgO Nanoparticles

preprint
submitted on 29.04.2021, 13:36 and posted on 30.04.2021, 05:12 by Martijn Zwijnenburg
evGW-BSE is used to predict the (band) edge states, fundamental gap, optical gap, exciton binding energy and UV-Vis absorption spectra for a series of cuboidal MgO rocksalt nanoparticles, the largest of with has 216 atoms and edges of 1 nm. The evolution of the electronic and optical properties with particle size was studied, where it was found that while the edge states and fundamental gap change with particle size, the optical gap remains essentially fixed for cuboid nanoparticles containing 48 atoms or more. The explanation for that observation is that while the optical gap is associated with an exciton that is well localised on the magnesium corner atoms and the oxygen atoms directly surrounding it, the edge states, while primarily localised on the magnesium corner atoms (electron) and oxygen corner atoms (hole), show significant delocalisation along the edges away from the corner atoms. The BSE/evGW optical gap for the smallest particles, the (MgO)4 cube, matches with that obtained independently from coupled cluster theory, while for the (MgO)32, a cube with edges of 0.6 nm, the BSE/evGW predicted excitation spectrum agrees well with the experimentally reported reflection spectra of MgO nanoparticles.

Funding

Elucidating the photochemistry of inorganic nanostructures

Engineering and Physical Sciences Research Council

Find out more...

Integration of Computation and Experiment for Accelerated Materials Discovery

Engineering and Physical Sciences Research Council

Find out more...

History

Email Address of Submitting Author

m.zwijnenburg@ucl.ac.uk

Institution

University College London

Country

United Kingdom

ORCID For Submitting Author

0000-0001-5291-2130

Declaration of Conflict of Interest

No conflicts of interest

Exports