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 journalArticle

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. Evaluating sulfur-tolerance of metal/Ce0.80Gd0.20O1.90 co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for solid oxide fuel cells

    Price, R., Grolig, J. G., Mai, A. & Irvine, J. T. S., Apr 2020, In : Solid State Ionics. 347, 115254.

    Research output: Contribution to journalArticle

  2. High oxide ion and proton conductivity in a disordered hexagonal perovskite

    Fop, S., McCombie, K. S., Wildman, E. J., Skakle, J. M. S., Irvine, J. T. S., Connor, P. A., Savaniu, C., Ritter, C. & Mclaughlin, A. C., 2 Mar 2020, In : Nature Materials. 7 p.

    Research output: Contribution to journalArticle

  3. Bandgap bowing in a zero-dimensional hybrid halide perovskite derivative: spin-orbit coupling: versus lattice strain

    Chatterjee, S., Payne, J., Irvine, J. T. S. & Pal, A. J., 28 Feb 2020, In : Journal of Materials Chemistry A. 8, 8, p. 4416-4427 12 p.

    Research output: Contribution to journalArticle

  4. Direct insight into the band structure of SrNbO3

    Bigi, C., Orgiani, P., Slawinska, J., Fujii, J., Irvine, J. T., Picozzi, S., Panaccione, G., Vobornik, I., Rossi, G., Payne, D. & Borgatti, F., 27 Feb 2020, In : Physical Review Materials. 4, 2, 7 p., 025006.

    Research output: Contribution to journalArticle

  5. Replacement of Ca by Ni in a perovskite titanate to yield a novel perovskite exsolution architecture for oxygen-evolution reactions

    Lee, J., Myung, J., Naden, A. B., Jeon, O. S., Shul, Y. G. & Irvine, J. T. S., 30 Jan 2020, In : Advanced Energy Materials. Early View, 1903693.

    Research output: Contribution to journalArticle

Related by journal

  1. 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 journalArticle

  2. Lévy defects in matrix-immobilized J aggregates: tracing intra-and intersegmental exciton relaxation

    Lüer, L., Rajendran, S. K., Stoll, T., Ganzer, L., Rehault, J., Coles, D. M., Lidzey, D., Virgili, T. & Cerullo, G., 2 Feb 2017, In : Journal of Physical Chemistry Letters. 8, 3, p. 547-552 6 p.

    Research output: Contribution to journalArticle

  3. Ultrafast Electronic Energy Transfer in an orthogonal molecular dyad

    Wiebeler, C., Plasser, F., Hedley, G. J., Ruseckas, A., Samuel, I. D. W. & Schumacher, S., 2 Mar 2017, In : Journal of Physical Chemistry Letters. 8, 5, p. 1086-1092 7 p.

    Research output: Contribution to journalArticle

  4. DEER sensitivity between iron centers and nitroxides in heme-containing proteins improves dramatically using broadband, high-field EPR

    Motion, C. L., Lovett, J. E., Bell, S., Cassidy, S. L., Cruickshank, P. A. S., Bolton, D. R., Hunter, R. I., El Mkami, H., Van Doorslaer, S. & Smith, G. M., 21 Apr 2016, In : Journal of Physical Chemistry Letters. 7, 8, p. 1411-1415 5 p.

    Research output: Contribution to journalArticle

ID: 266864924

Top