Ultrathin Single-Crystal Gold as a High-Performance Device Platform

This award will establish a device-ready wafer-based platform enabled by the controlled formation of large-area ultrathin crystals of gold. The work is motivated by an application space that is thriving in terms of state-of-the-art device demonstrations in nanophotonics and biosensing despite the use of ultrathin gold derived from tedious synthetic procedures and suboptimal nanofabrication processing techniques. Using a newly discovered gold microplate synthesis capable of realizing ultrathin gold at addressable positions, the research aims to fundamentally transform existing techniques with emphasis placed on the low-cost, high-throughput, and scalability needs of a manufacturing setting. The so-formed device platform will be validated through the fabrication and testing of first-of-their-kind digital biosensors. In doing so, the project will elevate the status of ultrathin crystalline gold as a technologically viable, high-performance nanomaterial. This research will also realize societal benefits through the training of graduate students, involving undergraduates in research projects focused on advanced manufacturing, and engaging K-12 students in activities designed to promote interest in STEM-related fields. Proof-of-principle device demonstrations in plasmonic and electroplasmonic circuitry, biosensing, metamaterials, nanolasers, and nanoparticle-on-mirror optical devices have definitively shown that single-crystal gold microplates are unrivaled in terms of the properties they offer and the device processing characteristics they enable. These advancements are, however, reliant on highly undesirable synthetic processes and, as such, provide no pathway for translating research excitement into a viable technology. This research aims to disrupt the status quo by (i) forwarding a new synthetic strategy that addresses the need for the precise placement of microplates on substrates surfaces at high yield in a manner that is amenable to batch processing, (ii) advancing the post-synthesis processing capabilities needed for scalable nanofabrication, and (iii) integrating these materials and processes into application-driven device platforms. Specific outcomes that will be targeted include (i) scaling microplate array fabrication to two-inch wafer sizes, (ii) establishing the first large-area processing route for nanoparticle-on-mirror configurations where the nanoparticles are arranged in periodic arrays with Rayleigh criterion separation, and (iii) demonstrating the first single-crystal microplate platform for digital biosensing with multiplexing capabilities. These new concepts, if successfully implemented, could provide a paradigm shift in the on-chip synthesis, processing, and application of ultrathin single-crystal gold. 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. NSF Award ID: 2514418 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Svetlana Neretina | Institution: University of Notre Dame, NOTRE DAME, IN | Award Amount: $479,971 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2514418 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2514418.html