Cu 2 ZnSnS 4 (CZTS) is a promising material for solar energy conversion, but synthesis of phase-pure, anisotropic CZTS nanocrystals remains a challenge. We demonstrate that the initial concentration (loading) of cationic precursors has a dramatic effect on the morphology (aspect ratio) and composition (internal architecture) of hexagonal wurtzite CZTS nanorods. Our experiments strongly indicate that Cu is the most reactive of the metal cations; Zn is next, and Sn is the least reactive. Using this reactivity series, we are able to purposely fine-tune the morphology (dots versus rods) and degree of axial phase segregation of CZTS nanocrystals. These results will improve our ability to fabricate CZTS nanostructures for photovoltaics and photocatalysis. KeywordsComposition control, CZTS, precursor loading, shape control ABSTRACT: Cu 2 ZnSnS 4 (CZTS) is a promising material for solar energy conversion, but synthesis of phase-pure, anisotropic CZTS nanocrystals remains a challenge. We demonstrate that the initial concentration (loading) of cationic precursors has a dramatic effect on the morphology (aspect ratio) and composition (internal architecture) of hexagonal wurtzite CZTS nanorods. Our experiments strongly indicate that Cu is the most reactive of the metal cations; Zn is next, and Sn is the least reactive. Using this reactivity series, we are able to purposely fine-tune the morphology (dots versus rods) and degree of axial phase segregation of CZTS nanocrystals. These results will improve our ability to fabricate CZTS nanostructures for photovoltaics and photocatalysis.

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