Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 142632

142632 - Scalable Nanomanufacturing of Highly-Uniform, Atomically-Thin 2d Nanoribbons With Ångström-Precise Edge Chirality 

Atomically-thin two-dimensional nanoribbons (2D-NRs) exhibit emergent quantum phenomena arising from tunable edge states and additional lateral confinement effects that are unique from their 2D monolayer counterparts. The ribbon width, layer thickness, edge chirality, and morphology of 2D-NRs dictate their intrinsic multi-physical properties. In the pursuit of advancing the synthesis of 2D-NRs, researchers have explored a myriad of both top-down and bottom-up approaches over the past two decades. Top-down approaches involve the sculpting or patterning of 2D materials down to the desired lateral nanoscale dimensions. Top-down strategies enable high throughput, making them viable options for scalable production. Nonetheless, these approaches suffer from a lack of precision in the dimensions and edge structures of 2D-NRs, which leads to inconsistencies in electrical conductivity, optical properties, and chemical reactivity. Bottom-up methods, characterized by their ability to assemble 2D-NRs with atomic or molecular precision, offer the advantage of creating nanoribbons with well-defined edges and uniform thickness. However, challenges arise in scalability, uniformity, and control over the nanoribbons' relative arrangement and position due to the intricate growth parameters. It remains difficult to achieve the optimal balance between the precision, uniformity, and scalability required for future application needs in high density integrated circuits, quantum computing, and sensing devices. 

To overcome the inherent limitations of conventional synthesis methods, we have developed a novel, purely mechanical method for the scalable assembly of 2D-NRs that operates under ambient conditions. By subjecting various 2D materials adhered to polymer substrates to excessive tensile strain, we can systematically induce parallel fractures across the entire crystal structure thereby segmenting them into nanoribbons. We systematically investigated the surface morphology and crystal structure of these monolayer nanoribbons. The resulting linear 2D-NR structures feature highly uniform width, spacing, and alignment, with ångström-precise edge chirality. An edge-to-edge angle deviation of less than 0.00019° along ribbons suggests the high parallelism inherent to each nanoribbon. The highly uniform and straight edges can minimize scattering of charge carriers, enhance the mechanical strength, and improve the chemical/thermal stability. In semiconductor 2D-NRs, the precise control over the edges allows for the manipulation of quantum confinement effects and bandgap tuning. Another notable feature of the 2D-NRs obtained by the proposed method is the potential for achieving exceptionally high aspect ratio between the ribbon length and width. Observations indicate that fractures uniformly span the entirety of the parental 2D flake, irrespective of its length, while the width of the resulting nanoribbons remains constant. Consequently, the aspect ratio of 2D-NRs can be tailored by using 2D flakes with different lengths. Furthermore, the proposed method shows well-tuned ribbon width through control over the strain magnitude, the global defect level in the Basal plane, or localized vacancies.

This generalizable capability of creating arbitrary 2D-NRs from a diverse range of 2D crystals paves the way for unprecedented opportunities in semiconductor and quantum device manufacturing. It opens a new route of employing purely mechanical methods in the scalable synthesis of 2D-NRs yet maintain high precision and uniformity.

Presenting Author: Zhewen Yin Department of Mechanical Engineering, University of South Florida

Presenting Author Biography: Zhewen Yin is currently pursuing his PhD in the Department of Mechanical Engineering at the University of South Florida, Tampa, FL, USA. His research focuses primarily on engineering and manufacturing of two-dimensional (2D) materials. He obtained his B.S. degree from University of Science and Technology of China, in 2016, followed by his M.S. degree from University of South Florida, in 2018.

Authors:

Zhewen Yin Department of Mechanical Engineering, University of South Florida
Darley (Daiyue) Wei University of South Florida
Ossie Douglas University of South Florida
Muhammad Shahbaz Rafique University of South Florida
Huijuan Zhao Clemson University
Michael Cai Wang University of South Florida