Oxidation/reduction cycles and their reversible effect on the dipole formation at CuInSe2 surfaces

Amala Elizabeth, Sudhir K. Sahoo, David Lockhorn, Alexander Timmer, Nabi Aghdassi, Helmut Zacharias, Thomas D. Kühne, Susanne Siebentritt, Hossein Mirhosseini, and Harry Mönig
Phys. Rev. Materials 4, 063401 – Published 8 June 2020
PDFHTMLExport Citation

Abstract

The defect-electronic properties of {112} microfaceted surfaces of epitaxially grown CuInSe2 thin films are investigated by scanning tunneling spectroscopy and photoelectron spectroscopy techniques after various surface treatments. The intrinsic CuInSe2 surface is found to be largely passivated in terms of electronic defect levels in the band-gap region. However, surface oxidation leads to an overall high density of defect levels in conjunction with a considerable net surface dipole, which persists even after oxide removal. Yet, a subsequent annealing under vacuum restores the initial condition. Such oxidation/reduction cycles are reversible for many times providing robust control of the surface and interface properties in these materials. Based on ab initio simulations, a mechanism where oxygen dissociatively adsorbs and subsequently diffuses to a subsurface site is proposed as the initial step of the observed dipole formation. Our results emphasize the relevance of oxidation-induced dipole effects at the thin film surface and provide a comprehensive understanding toward passivation strategies of these surfaces.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 4 February 2020
  • Accepted 15 May 2020

DOI:https://doi.org/10.1103/PhysRevMaterials.4.063401

©2020 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Amala Elizabeth1,2, Sudhir K. Sahoo3, David Lockhorn1,2, Alexander Timmer1,2, Nabi Aghdassi4, Helmut Zacharias1,2, Thomas D. Kühne3, Susanne Siebentritt5, Hossein Mirhosseini3, and Harry Mönig1,2,*

  • 1Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm Strasse 10, 48149 Münster, Germany
  • 2Center for Nanotechnology (CeNTech), Heisenberg Strasse 11, 48149 Münster, Germany
  • 3Dynamics of Condensed Matter and Center for Sustainable Systems Design, Theoretische Chemie, Universität Paderborn, Warburger Strasse 100, 33098 Paderborn, Germany
  • 4Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung- Plasmaphysik, 52425 Jülich, Germany
  • 5Laboratory for photovoltaics, Université du Luxembourg, rue du Brill 41, 4422 Belvaux, Luxembourg

  • *harry.moenig@uni-muenster.de

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 4, Iss. 6 — June 2020

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Materials

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×