Microstructural characterization of chemical bath deposited and sputtered Zn(O,S) buffer layers

E. Gautron, M. Buffière, S. Harel, L. Assmann, L. Arzel, L. Brohan, J. Kessler, N. Barreau

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The present work aims at investigating the microstructure of Zn(O,S) buffer layers relative to their deposition route, namely either chemical bath deposition (CBD) or RF co-sputtering process (PVD) under pure Ar. The core of the study consists of cross-sectional transmission electron microscopy (TEM) characterization of the differently grown Zn(O,S) thin films on co-evaporated Cu(In,Ga)Se2 (CIGSe) absorbers. It shows that the morphology of Zn(O,S) layer deposited on CIGSe using CBD process is made of a thin layer of well oriented ZnS sphalerite-(111) and/or ZnS wurtzite-(0002) planes parallel to CIGSe chalcopyrite-(112) planes at the interface with CIGSe followed by misoriented nanometer-sized ZnS crystallites in an amorphous phase. As far as (PVD)Zn(O,S) is concerned, the TEM analyses reveal two different microstructures depending on the S-content in the films: for [S] / ([O] + [S]) = 0.6, the buffer layer is made of ZnO zincite and ZnS wurtzite crystallites grown nearly coherently to each other, with (0002) planes nearly parallel with CIGSe-(112) planes, while for [S] / ([O] + [S]) = 0.3, it is made of ZnO zincite type crystals with O atoms substituted by S atoms, with (0002) planes perfectly aligned with CIGSe-(112) planes. Such microstructural differences can explain why photovoltaic performances are dependent on the Zn(O,S) buffer layer deposition route.

Original languageEnglish
Pages (from-to)175-179
Number of pages5
JournalThin Solid Films
Issue number1
Publication statusPublished - 15 May 2013



  • CBD
  • CIGSe
  • Cross-sectional TEM
  • Microstructure
  • PVD
  • Zn(O,S) buffer layer

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

Gautron, E., Buffière, M., Harel, S., Assmann, L., Arzel, L., Brohan, L., Kessler, J., & Barreau, N. (2013). Microstructural characterization of chemical bath deposited and sputtered Zn(O,S) buffer layers. Thin Solid Films, 535(1), 175-179. https://doi.org/10.1016/j.tsf.2012.10.040