Scalable manufacturing procedures that can generate nanoscale patterns with no natural geometric analog are useful in the formation of nanostructured device structures. Ultrathin nanostructures (one thousandth the diameter of a human hair) composed of metallic building units can control the flow of light in new ways and transform modern bulky devices. Such surfaces will accelerate progress in fabricating new materials and the emergence of domestic industries involving quantum communication, enhanced light collection for solar cells, and compact light emitters for optical circuits. Historically, the creation of complex nanostructured designs has required precise, slow-production tools that are expensive and time consuming. This research will explore highly reproducible and broadly flexible methods to form surfaces with unconventional geometries for light manipulation from simple and accessible lithography tools. By incorporating the expertise of materials science engineers and computational scientists, this research expands our nation?s leadership in scalable manufacturing processes critical for quantum information processing and anti-counterfeiting for national security. This work will also increase scientific literacy through a combination of hands-on demonstrations to under-represented communities and widely available video tutorials depicting the techniques used in this research.
Superimposing periodic arrays at specific rotational offsets produce interference patterns known as moiré patterns. Depending on the offset angle, the moiré pattern may be highly symmetric or aperiodic. Stacking two layers of 2D atomic materials at a ?magic angle? has resulted in electronic moiré potentials that show unexpected physical properties including superconductivity and topological excitonic states. This project develops scalable nanofabrication methods to generate large-area photonic moiré nanostructures by building on moiré nanolithography. Although periodic nanostructures can be fabricated by techniques such as nanoimprinting and laser interference lithography, the patterns are typically limited to arrays with a single repeating unit. With multiple exposures and a library of periodic masks, however, moiré nanolithography can drastically expand the number of symmetries beyond those realized by stacking 2D atomic materials. Pattern formation, transfer, and processing will be optimized to investigate photonic properties that may only be realized by nanoarchitectures organized into super-symmetries. One application will focus on the nanomanufacturing of photonic structures that may support topological states or that can be coupled to quantum emitters for unprecedented light-matter interactions.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.