Skip to content

Research at St Andrews

Controlling the energy-level alignment of silicon carbide nanocrystals by combining surface chemistry with quantum confinement

Research output: Contribution to journalArticlepeer-review

Author(s)

Atta Ul Haq, Marius Buerkle, Sadegh Askari, Conor Rocks, Chengsheng Ni, Vladimir Švrček, Paul Maguire, John T.S. Irvine, Davide Mariotti

School/Research organisations

Abstract

The knowledge of band edges in nanocrystals (NCs) and quantum-confined systems is important for band alignment in technologically significant applications such as water purification, decomposition of organic compounds, water splitting, and solar cells. While the band energy diagram of bulk silicon carbides (SiCs) has been studied extensively for decades, very little is known about its evolution in SiC NCs. Moreover, the interplay between quantum confinement and surface chemistry gives rise to unusual electronic properties and remains barely understood. Here, we report for the first time the complete band energy diagram of SiC NCs synthesized such that they span the regime from strong to intermediate to weak quantum confinement. The absolute positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals show clear size dependence. While the HOMO level follows the expected behavior for quantum-confined electronic states, the LUMO energy shifts below the bulk conduction band minimum, which cannot be explained by a simple quantum confinement caused by the size effect. We show that this effect is a result of the interplay between quantum confinement and the formation of surface states due to partial and site-selective oxygen passivation.

Close

Details

Original languageEnglish
Pages (from-to)1721-1728
Number of pages8
JournalJournal of Physical Chemistry Letters
Volume11
Issue number5
Early online date10 Feb 2020
DOIs
Publication statusPublished - 5 Mar 2020

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Achieving strong coherency for a composite electrode via one-pot method with enhanced electrochemical performance in reversible solid oxide cells

    Tian, Y., Wang, W., Liu, Y., Naden, A., Xu, M., Wu, S., Chi, B., Pu, J. & Irvine, J. T. S., 19 Mar 2021, In: ACS Catalysis. 11, 6, p. 3704-3714 11 p.

    Research output: Contribution to journalArticlepeer-review

  2. Alkaline modified A-site deficient perovskite catalyst surface with exsolved nanoparticles and functionality in biomass valorisation

    Umar, A., Neagu, D. & Irvine, J. T. S., 1 Mar 2021, In: Biofuel Research Journal. 8, 1, p. 1342-1350 9 p.

    Research output: Contribution to journalArticlepeer-review

  3. Non-stoichiometry, structure and properties of proton-conducting perovskite oxides

    Li, S. & Irvine, J. T. S., Mar 2021, In: Solid State Ionics. 361, 115571.

    Research output: Contribution to journalReview articlepeer-review

  4. Upscaling of co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for solid oxide fuel cells: a progress report on a decade of academic-industrial collaboration

    Price, R., Cassidy, M., Grolig, J. G., Longo, G. G., Weissen, U. G., Mai, A. G. & Irvine, J. T. S., 12 Feb 2021, In: Advanced Energy Materials. Early View, 21 p., 2003951.

    Research output: Contribution to journalReview articlepeer-review

  5. Microwave irradiation synthesis to obtain La0.7-xPrxCa0.3MnO3 perovskites: electrical and electrochemical performance

    Ferrel-Alvarez, A. C., Domínguez-Crespo, M. A., Cong, H., Torres-Huerta, A. M., Palma-Ramírez, D. & Irvine, J. T. S., 15 Jan 2021, In: Journal of Alloys and Compounds. 851, 156882.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. Investigation of intramolecular through-space charge-transfer states in donor-acceptor charge-transfer systems

    Kumar, S., Franca, L. G., Stavrou, K., Crovini, E., Cordes, D. B., Slawin, A. M. Z., Monkman, A. P. & Zysman-Colman, E., 15 Mar 2021, In: Journal of Physical Chemistry Letters. 12, p. 2820-2830 11 p.

    Research output: Contribution to journalArticlepeer-review

  2. Efficient luminescence from CsPbBr3 nanoparticles embedded in Cs4PbBr6

    Bao, Z., Tseng, Y. J., You, W., Zheng, W., Chen, X., Mahlik, S., Lazarowska, A., Lesniewski, T., Grinberg, M., Ma, C., Sun, W., Zhou, W., Liu, R. S. & Attfield, J. P., 17 Sep 2020, In: Journal of Physical Chemistry Letters. 11, 18, p. 7637-7642 6 p.

    Research output: Contribution to journalArticlepeer-review

  3. Interaction of B12F122- with All-cis 1,2,3,4,5,6 hexafluorocyclohexane in the gas phase

    Lecours, M. J., Marta, R. A., Steinmetz, V., Keddie, N., Fillion, E., O'Hagan, D., McMahon, T. B. & Hopkins, W. S., 5 Jan 2017, In: Journal of Physical Chemistry Letters. 8, 1, p. 109-113

    Research output: Contribution to journalArticlepeer-review

ID: 266864924

Top