Research

Nature of the band gap and origin of the conductivity of PbO(2) revealed by theory and experiment


Reference:

Scanlon, D. O., Kehoe, A. B., Watson, G. W., Jones, M. O., David, W. I. F., Payne, D. J., Egdell, R. G., Edwards, P. P. and Walsh, A., 2011. Nature of the band gap and origin of the conductivity of PbO(2) revealed by theory and experiment. Physical Review Letters, 107 (24), 246402.

Related documents:

[img]
Preview
PDF (Walsh_PRL_2011_107_246402.pdf) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (3104kB) | Preview

    Official URL:

    http://dx.doi.org/10.1103/PhysRevLett.107.246402

    Abstract

    Lead dioxide has been used for over a century in the lead-acid battery. Many fundamental questions concerning PbO(2) remain unanswered, principally: (i) is the bulk material a metal or a semiconductor, and (ii) what is the source of the high levels of conductivity? We calculate the electronic structure and defect physics of PbO(2), using a hybrid density functional, and show that it is an n-type semiconductor with a small indirect band gap of similar to 0.2 eV. The origin of electron carriers in the undoped material is found to be oxygen vacancies, which forms a donor state resonant in the conduction band. A dipole-forbidden band gap combined with a large carrier induced Moss-Burstein shift results in a large effective optical band gap. The model is supported by neutron diffraction, which reveals that the oxygen sublattice is only 98.4% occupied, thus confirming oxygen substoichiometry as the electron source.

    Details

    Item Type Articles
    CreatorsScanlon, D. O., Kehoe, A. B., Watson, G. W., Jones, M. O., David, W. I. F., Payne, D. J., Egdell, R. G., Edwards, P. P. and Walsh, A.
    DOI10.1103/PhysRevLett.107.246402
    DepartmentsFaculty of Science > Chemistry
    Research CentresCentre for Sustainable Chemical Technologies
    Publisher StatementWalsh_PRL_2011_107_246402.pdf: Scanlon, D. O., Kehoe, A. B., Watson, G. W., Jones, M. O., David, W. I. F., Payne, D. J., Egdell, R. G., Edwards, P. P. and Walsh, A., 2011. Nature of the band gap and origin of the conductivity of PbO(2) revealed by theory and experiment. Physical Review Letters, 107 (24), 246402. © 2011 American Physical Society.
    RefereedYes
    StatusPublished
    ID Code27993

    Export

    Actions (login required)

    View Item

    Document Downloads

    More statistics for this item...