---
_id: '19823'
abstract:
- lang: eng
  text: 'Individual grains of chalcopyrite solar cell absorbers can facet in different
    crystallographic directions at their surfaces. To gain a deeper understanding
    of the junction formation in these devices, we correlate variations in the surface
    facet orientation with the defect electronic properties. We use a combined analytical
    approach based on scanning tunneling spectroscopy (STS), scanning electron microscopy,
    and electron back scatter diffraction (EBSD), where we perform these experiments
    on identical surface areas as small as 2 × 2 µm2 with a lateral resolution well
    below 50 nm. The topography of the absorber surfaces indicates two main morphological
    features: micro-faceted, long basalt-like columns and their short nano-faceted
    terminations. Our STS results reveal that the long columns exhibit spectral signatures
    typical for the presence of pronounced oxidation-induced surface dipoles in conjunction
    with an increased density of electronic defect levels. In contrast, the nano-faceted
    terminations of the basalt-like columns are largely passivated in terms of electronic
    defect levels within the band gap region. Corresponding crystallographic data
    based on EBSD experiments show that the surface of the basalt-like columns can
    be assigned to intrinsically polar facet orientations, while the passivated terminations
    are assigned to non-polar planes. Ab-initio calculations suggest that the polar
    surfaces are more prone to oxidation and resulting O-induced defects, in comparison
    to non-polar planes. Our results emphasize the correlation between morphology,
    surface facet orientations and surface electronic properties. Furthermore, this
    work aids in gaining a fundamental understanding of oxidation induced lateral
    inhomogeneities in view of the p-n junction formation in chalcopyrite thin-film
    solar cells.'
author:
- first_name: Amala
  full_name: Elizabeth, Amala
  last_name: Elizabeth
- first_name: Hauke
  full_name: Conradi, Hauke
  last_name: Conradi
- first_name: Sudhir
  full_name: K. Sahoo, Sudhir
  last_name: K. Sahoo
- first_name: Tim
  full_name: Kodalle, Tim
  last_name: Kodalle
- first_name: Christian
  full_name: A. Kaufmann, Christian
  last_name: A. Kaufmann
- first_name: Thomas
  full_name: Kühne, Thomas
  id: '49079'
  last_name: Kühne
- first_name: Hossein
  full_name: Mirhosseini, Hossein
  id: '71051'
  last_name: Mirhosseini
  orcid: https://orcid.org/0000-0001-6179-1545
- first_name: Daniel
  full_name: Abou-Ras, Daniel
  last_name: Abou-Ras
- first_name: Harry
  full_name: Mönig, Harry
  last_name: Mönig
citation:
  ama: Elizabeth A, Conradi H, K. Sahoo S, et al. Correlating facet orientation, defect-level
    density and dipole layer formation at the surface of polycrystalline CuInSe2 thin
    films. <i>Acta Materialia</i>. 2020;200. doi:<a href="https://doi.org/10.1016/j.actamat.2020.09.028">https://doi.org/10.1016/j.actamat.2020.09.028</a>
  apa: Elizabeth, A., Conradi, H., K. Sahoo, S., Kodalle, T., A. Kaufmann, C., Kühne,
    T., … Mönig, H. (2020). Correlating facet orientation, defect-level density and
    dipole layer formation at the surface of polycrystalline CuInSe2 thin films. <i>Acta
    Materialia</i>, <i>200</i>. <a href="https://doi.org/10.1016/j.actamat.2020.09.028">https://doi.org/10.1016/j.actamat.2020.09.028</a>
  bibtex: '@article{Elizabeth_Conradi_K. Sahoo_Kodalle_A. Kaufmann_Kühne_Mirhosseini_Abou-Ras_Mönig_2020,
    title={Correlating facet orientation, defect-level density and dipole layer formation
    at the surface of polycrystalline CuInSe2 thin films}, volume={200}, DOI={<a href="https://doi.org/10.1016/j.actamat.2020.09.028">https://doi.org/10.1016/j.actamat.2020.09.028</a>},
    journal={Acta Materialia}, author={Elizabeth, Amala and Conradi, Hauke and K.
    Sahoo, Sudhir and Kodalle, Tim and A. Kaufmann, Christian and Kühne, Thomas and
    Mirhosseini, Hossein and Abou-Ras, Daniel and Mönig, Harry}, year={2020} }'
  chicago: Elizabeth, Amala, Hauke Conradi, Sudhir K. Sahoo, Tim Kodalle, Christian
    A. Kaufmann, Thomas Kühne, Hossein Mirhosseini, Daniel Abou-Ras, and Harry Mönig.
    “Correlating Facet Orientation, Defect-Level Density and Dipole Layer Formation
    at the Surface of Polycrystalline CuInSe2 Thin Films.” <i>Acta Materialia</i>
    200 (2020). <a href="https://doi.org/10.1016/j.actamat.2020.09.028">https://doi.org/10.1016/j.actamat.2020.09.028</a>.
  ieee: A. Elizabeth <i>et al.</i>, “Correlating facet orientation, defect-level density
    and dipole layer formation at the surface of polycrystalline CuInSe2 thin films,”
    <i>Acta Materialia</i>, vol. 200, 2020.
  mla: Elizabeth, Amala, et al. “Correlating Facet Orientation, Defect-Level Density
    and Dipole Layer Formation at the Surface of Polycrystalline CuInSe2 Thin Films.”
    <i>Acta Materialia</i>, vol. 200, 2020, doi:<a href="https://doi.org/10.1016/j.actamat.2020.09.028">https://doi.org/10.1016/j.actamat.2020.09.028</a>.
  short: A. Elizabeth, H. Conradi, S. K. Sahoo, T. Kodalle, C. A. Kaufmann, T. Kühne,
    H. Mirhosseini, D. Abou-Ras, H. Mönig, Acta Materialia 200 (2020).
date_created: 2020-10-01T09:19:55Z
date_updated: 2022-01-06T06:54:13Z
department:
- _id: '613'
doi: https://doi.org/10.1016/j.actamat.2020.09.028
intvolume: '       200'
keyword:
- Chalcopyrite absorber
- Scanning tunneling spectroscopy
- Electron backscatter diffraction
- Density functional theory
- Surface dipole
language:
- iso: eng
project:
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: Acta Materialia
publication_identifier:
  issn:
  - 1359-6454
status: public
title: Correlating facet orientation, defect-level density and dipole layer formation
  at the surface of polycrystalline CuInSe2 thin films
type: journal_article
user_id: '71692'
volume: 200
year: '2020'
...