Maggio, E., Martsinovich, N. and Troisi, A. (2016) Continuum and atomistic description of excess electrons in TiO2. Journal of Physics: Condensed Matter, 28 (7). ISSN 0953-8984
Abstract
The modelling of an excess electron in a semiconductor in a prototypical dye sensitised solar cell is carried out using two complementary approaches: atomistic simulation of the TiO2 nanoparticle surface is complemented by a dielectric continuum model of the solvent–semiconductor interface. The two methods are employed to characterise the bound (excitonic) states formed by the interaction of the electron in the semiconductor with a positive charge opposite the interface. Density-functional theory (DFT) calculations show that the excess electron in TiO2 in the presence of a counterion is not fully localised but extends laterally over a large region, larger than system sizes accessible to DFT calculations. The numerical description of the excess electron at the semiconductor–electrolyte interface based on the continuum model shows that the exciton is also delocalised over a large area: the exciton radius can have values from tens to hundreds of Ångströms, depending on the nature of the semiconductor (characterised by the dielectric constant and the electron effective mass in our model).
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016 IOP Publishing. This is an author produced version of a paper subsequently published in Journal of Physics: Condensed Matter. Uploaded in accordance with the publisher's self-archiving policy |
Keywords: | TiO2; exciton; excess electron; continuum model |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 19 Nov 2015 15:25 |
Last Modified: | 05 Nov 2017 17:58 |
Published Version: | http://dx.doi.org/10.1088/0953-8984/28/7/074004 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/0953-8984/28/7/074004 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:91418 |