A crystallographic description of experimentally identified formation reactions of Cu(In,Ga)Se{sub 2}

Journal Article · Tue Aug 15 04:00:00 EDT 2006 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2006.04.033· OSTI ID:20905389

Hergert, F ^[1]; Jost, S ^[1]; Hock, R ^[1]; Purwins, M ^[2]

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1. Chair for Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany)
2. Crystal Growth Laboratory, Department of Materials Science VI, University of Erlangen-Nuernberg, Martensstr. 7, D-91058 Erlangen (Germany)

This work describes solid-state reactions for the formation of the chalcopyrite compounds CuInSe{sub 2}, CuGaSe{sub 2} and Cu(In,Ga)Se{sub 2} on atomic scale. The most important chalcopyrite formation reactions which were identified by the authors by real-time in situ X-ray diffraction in preceding experiments are (A) CuSe+InSe{sup {yields}}CuInSe{sub 2} (B) Cu{sub 2}Se+2 InSe+Se{sup {yields}}2 CuInSe{sub 2} and (C) Cu{sub 2}Se+In{sub 2}Se{sub 3}{sup {yields}}2 CuInSe{sub 2}. During the selenistaion of a metallic precursor containing gallium a separate fourth reaction occurs: (D) Cu{sub 2}Se+Ga{sub 2}Se{sub 3}{sup {yields}}2 CuGaSe{sub 2}. The quaternary compound is finally formed by interdiffusion of CuInSe{sub 2} with CuGaSe{sub 2} (E). These five reactions differ in their activation energy and reaction speed. We explain these differences qualitatively by analysing the involved crystal structures for each reaction. It turns out that all reactions involved in the formation of Cu(In,Ga)Se{sub 2} are promoted by epitaxial relations, which facilitates the formation of polycrystalline thin films at temperatures much below those necessary for single crystal growth. Recommendations for the growth of larger grains of Cu(In,Ga)Se{sub 2} containing fewer defects are given. - Graphical abstract: The epitaxial connection of the crystal structures of {beta}-Cu{sub 2}Se (bottom) and {beta}-In{sub 2}Se{sub 3} (top) is the initiating step of one possible solid-state reaction for the formation of {alpha}-CuInSe{sub 2}.

• OSTI ID: 20905389
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 8 Vol. 179; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
COPPER SELENIDES
CRYSTAL DEFECTS
CRYSTAL GROWTH
CRYSTALLOGRAPHY
EPITAXY
GALLIUM SELENIDES
INDIUM SELENIDES
MONOCRYSTALS
POLYCRYSTALS
QUATERNARY COMPOUNDS
THIN FILMS
X-RAY DIFFRACTION