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The Cheminar

Tuesday, February 21, 2023
11:00 a.m. - 12:00 p.m.

Add to Calendar 2023-02-21 11:00:00 2023-02-21 12:00:00 The Cheminar Top-down Production of Macroscopic Monolayers for Study of Static and Dynamical Properties Two dimensional (2D) materials and their artificial structures hold great promises for electronic, optoelectronic, and electrochemical applications. The best quality monolayers for exploring the exotic quantum properties so far are mostly produced by scotch tape exfoliation, which is stochastic and often yields microscopic sized monolayers. On the other hand, bottom-up growth techniques such as chemical vapor deposition often produces monolayers lower in quality. Beyond the Scotch tape exfoliation, we developed a few new scalable and controllable top-down processes to exfoliate a variety of van der Waals (vdW) single crystals into monolayers and monolayer nanoribbons with high yield, high quality, and macroscopic dimensions. High-quality and largearea crystals will allow us to further assemble them into artificial heterostructures. The monolayers and other 2D artificial structures have been demonstrated to achieve enhanced nonlinear optical responses, and integrate into multiple pump probe techniques as electron diffractions to explore the key static and dynamic properties in these low dimensional systems. Obtaining high quality materials with enhanced yield will not only facilitate the basic research, but also take us one step closer to mass production and commercialization of the 2D devices in the future. About the Speaker Dr. Fang Liu is an assistant professor of chemistry at Stanford University. Her research is focused on the light induced dynamics of solid low dimensional materials and construction of low dimensional artificial structures. Prior to her current position, she was a DOE Office of Energy Efficiency and Renewable Energy (EERE) postdoctoral fellow in the group of Prof. Xiaoyang Zhu at Columbia University. Her postdoctoral research focused on using femtosecond extreme UV in probing time and angle resolved photoemission spectroscopy of 2D materials. Prior to working in Columbia, she worked under the direction of Prof. Marsha I Lester at University of Pennsylvania. She received her Ph.D. in 2015 and worked as a postdoc in the same group in 2016. At UPenn, she used time resolved spectroscopic techniques to study spectroscopy and photochemistry of Criegee intermediates. She received her B.S. in chemistry at Peking University in 2010. Location: Classroom Building CR 170 3601 Pacific Ave, Stockton, CA 95211, USA College of the Pacific College of the Pacific America/Los_Angeles public

Top-down Production of Macroscopic Monolayers for Study of Static and Dynamical Properties

Two dimensional (2D) materials and their artificial structures hold great promises for electronic, optoelectronic, and electrochemical applications. The best quality monolayers for exploring the exotic quantum properties so far are mostly produced by scotch tape exfoliation, which is stochastic and often yields microscopic sized monolayers. On the other hand, bottom-up growth techniques such as chemical vapor deposition often produces monolayers lower in quality. Beyond the Scotch tape exfoliation, we developed a few new scalable and controllable top-down processes to exfoliate a variety of van der Waals (vdW) single crystals into monolayers and monolayer nanoribbons with high yield, high quality, and macroscopic dimensions. High-quality and largearea crystals will allow us to further assemble them into artificial heterostructures. The monolayers and other 2D artificial structures have been demonstrated to achieve enhanced nonlinear optical responses, and integrate into multiple pump probe techniques as electron diffractions to explore the key static and dynamic properties in these low dimensional systems. Obtaining high quality materials with enhanced yield will not only facilitate the basic research, but also take us one step closer to mass production and commercialization of the 2D devices in the future.

About the Speaker
Dr. Fang Liu is an assistant professor of chemistry at Stanford University. Her research is focused on the light induced dynamics of solid low dimensional materials and construction of low dimensional artificial structures. Prior to her current position, she was a DOE Office of Energy Efficiency and Renewable Energy (EERE) postdoctoral fellow in the group of Prof. Xiaoyang Zhu at Columbia University. Her postdoctoral research focused on using femtosecond extreme UV in probing time and angle resolved photoemission spectroscopy of 2D materials. Prior to working in Columbia, she worked under the direction of Prof. Marsha I Lester at University of Pennsylvania. She received her Ph.D. in 2015 and worked as a postdoc in the same group in 2016. At UPenn, she used time resolved spectroscopic techniques to study spectroscopy and photochemistry of Criegee intermediates. She received her B.S. in chemistry at Peking University in 2010.

Location: Classroom Building CR 170