Speaker: YANG LIU
Topic: MIXED-DIMENSIONAL VAN DER WAALS HETEROSTRUCTURE: FROM ARTIFICIAL ASSEMBLY TO SCALABLE SYNTHESIS
Date: WEDNESDAY MAY 4, 2022
Time: 10:00 – 11:00 am
Meeting ID: 970 6530 5821
Semiconducting transition-metal dichalcogenides (s-TMDs) have attracted extensive attention for fundamental studies and novel devices, particularly at the monolayer level. Van der Waals (vdW) integration of mixed-dimensional materials creates a new generation of vdW heterostructures beyond the limits set by lattice matching and processing compatibility requirements in conventional bonded heterostructures, as exemplified by the recent blossom in 2D materials. In this talk, I will first discuss our recent work establishing a mixed-dimensional strain- and doping-free device platform to build efficient contacts on ultrapure monolayer WSe2 and describe unconventional contacting behavior at the quasi-intrinsic limit by combing contact end and front resistance measurements. Next, I will talk about the artificially tailored ferroelectrics from ultraclean WSe2 that may host great promise for building ferroelectric devices at the atomically thin limit and identify the phase transition order experimentally. Next, I will talk about the scalable synthesis of mixed-dimensional metallic TMDs and semiconducting TMDs array that could naturally serve as high-quality vdW contacts for exploring fundamental physics and promises a scalable pathway to high-performance devices. Finally, I will discuss how these findings pave the way for further exploration of dynamically reconfigurable devices.
Yang Liu is currently a Postdoctoral Research Scientist in the Department of Mechanical Engineering at Columbia University, working with Prof. James Hone. Prior to joining Columbia, he received his Ph.D. from the EE department at Peking University under the supervision of Prof. Lian-Mao Peng, after which he did a short postdoc at UCLA with Prof. Xiangfeng Duan. His research efforts have focused on nanomaterials, nanodevices, and nano systems, with his Ph.D. studies on 1D carbon nanotubes and postdoc work on van der Waals 2D materials. He is the recipient of NT18 Best Young Scientist award.
All are welcome!