ABSTRACT

This Faculty Early Career Development (CAREER) grant supports research in the scalable nanomanufacturing of two-dimensional topological materials and the control of their structures and properties for high-performance quantum devices. The target materials are tellurene nanoribbons, which have potential applications in nanoelectronics, mid-infrared photonics, and wearable sensors. The project employs droplet-based flow reactors to identify the nucleation and growth mechanisms in these materials and gain the critical process-structure-property knowledge required for optimal production of tellurene nanoribbons with desired properties. The capability to manufacture high-quality two-dimensional quantum materials contributes significantly to the nation's economy and advances prosperity and welfare. The award aligns well with NSF's Quantum Leap Big Idea because two-dimensional crystals are candidate materials for next-generation quantum technologies in sensors, computing and communications. The research is holistically complemented by establishing an inclusive and flexible educational and outreach program based on curriculum development, industrial experience in college education, K-12 students, women and underrepresented minority outreach for training a high-quality future manufacturing workforce. This project allows advances in the knowledge base in material science, quantum engineering, nanotechnology and advanced manufacturing.

Two-dimensional quantum spin Hall materials, such as tellurene nanoribbons, host topologically protected edge states that can enable fast charge transport with minimum power dissipation for high-speed, energy-efficient electronics. The critical challenges to deploying these materials are to manufacture them without expensive epitaxial substrates and control over their dimensions, phase, and defect content for practical applications. Continuous flow processes based on droplet reactors present multiple benefits over conventional batch approaches to fabricate nanomaterials. It enables excellent process homogeneity and reproducibility, rapid screening of reaction parameters, fully automated control, and customized products with high throughput at reasonable costs. Typically, the flow-synthesized nanomaterials are nanocrystals with particle-like morphologies. The scientific understanding and technical capability for manufacturing two-dimensional materials using flow processes are missing. This research is to discover the fundamental basis for producing, engineering, and deploying tellurene nanoribbons for practical quantum spin Hall device applications through scalable substrate-agnostic continuous nanomanufacturing processes. This project's research objectives are to (i) establish the droplet-based flow manufacturing capability for producing two-dimensional tellurene nanoribbons with controlled properties, (ii) develop a physics-based, data-driven theoretical framework for guiding and understanding the experiments, and (iii) characterize the materials and devices to identify the process-structure-property-performance relations. The continuous flow process employs in-situ and ex-situ characterization combined with theoretical exploration to understand the chemical pathways critical to engineering the nucleation and growth of tellurene nanoribbons with tailored properties for quantum device manufacturing.

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.