Copper alkanethiolates are organometallic precursors that have been used to form Cu2S nanodisks upon thermal decomposition. Here, we demonstrate that molecular assembly of Cu alkanethiolates into an ordered liquid crystalline mesophase plays an essential role in templating the disk morphology of the solid-state product. To examine this templating effect, we synthesize Cu alkanethiolate precursors with alkane tails of varying chain length and sterics. We demonstrate that short chain precursors produce two-dimensional (2D) nanosheets of Cu2S, while longer-chained variants produce Cu2S nanodisks exclusively. This work provides new insights into the use of liquid crystalline phases as templates for nanocrystal synthesis and as a potential route for achieving highly anisotropic inorganic nanostructures.

The focused helium ion beam is ideally suited to precision milling of thin films avoiding implantation artifacts.