Thin film preparation of semiconducting iron pyrite

Greg Smestad, Ahmed Ennaoui, Sebastian Fiechter, Wolfgang Hofmann, Helmut Tributsch

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Pyrite (FeS2) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 105 cm-1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, SIO. It is postulated that for the material FeS2-x, if x is not zero, a high point defect concentration results from replacing S2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsClaes G. Granqvist, Carl M. Lampert
Place of PublicationBellingham, WA, United States
PublisherPubl by Int Soc for Optical Engineering
Pages67-78
Number of pages12
Volume1272
ISBN (Print)0819403199
Publication statusPublished - 1990
Externally publishedYes
EventOptical Materials Technology for Energy Efficiency and Solar Energy Conversion IX - Hague, Neth
Duration: 12 Mar 199013 Mar 1990

Other

OtherOptical Materials Technology for Energy Efficiency and Solar Energy Conversion IX
CityHague, Neth
Period12/3/9013/3/90

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ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Smestad, G., Ennaoui, A., Fiechter, S., Hofmann, W., & Tributsch, H. (1990). Thin film preparation of semiconducting iron pyrite. In C. G. Granqvist, & C. M. Lampert (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 1272, pp. 67-78). Publ by Int Soc for Optical Engineering.