Organic amphiphilic block copolymers swelled by carbon precursors self-assemble into a cocontinuous network mesophase via solvent vapor annealing. After carbonization in an inert atmosphere, the resulting mesoporous resin/carbon thin films template the nanostructures of amorphous silicon backfilled through chemical vapor deposition. The thermal stability of the templates derived from polymers is sufficient to allow for nanosecond transient laser heating to temperatures upward of 1400 °C. Melting and crystallization of Si during this highly non-equilibrium ultrafast time scale enable conformal template backfilling with the polycrystalline silicon inheriting the mesostructural order of the 3D resin/carbon templates. Detailed analysis of grazing incidence small-angle X-ray scattering data reveals symmetry reduction from cubic alternating gyroids to orthorhombic networks with D2 point group symmetry. Such unique nanostructures from block copolymers obtained under non-equilibrium laser heating conditions could pave the way towards topological photonic and phononic quantum metamaterials.

Crystalline inorganic nanomaterials templated from block copolymers: Non-equilibrium processing and unique topology from reduced symmetry

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.