Fundamental Properties and Device Prospect of Emerging Two-Dimensional Materials
Abstract: In this talk, I will discuss our recent work in developing novel electronic and photonic devices based on the anisotropic properties of low-symmetry two-dimensional (2D) materials, including black phosphorus (BP) and its isoelectronic materials such as the monochalcogenides of Group IV elements. High mobility, narrow gap BP thin film (0.3 eV in bulk) fill the energy space between zero-gap graphene and large-gap TMDCs, making it a promising material for mid-infrared and long wavelength infrared optoelectronics. Most importantly, its anisotropic nature within the plane of the layers allow for the realization of conceptually new electronic and photonic devices. Here, I will first present our work in understanding the fundamental electronic and optical properties of low-symmetry 2D materials such as BP using a newly developed scanning ultrafast electron microscopy (SUEM) technique and photoluminescence spectroscopy. Our recent the study of bandgap tuning in BP and the demonstration of a polarization sensitive BP mid-IR detector will then be presented. In the second half of my talk, I will discuss our work on developing two dimensional materials based artificial synaptic devices for neuromorphic electronics, including emulating the heterogeneity in synaptic connections using the anisotropic properties of BP and a tunable memristive device as a reconfigurable synapse. I will conclude with remarks on promising future research directions of low-symmetry electronics based on anisotropic 2D materials and how their novel properties is expected to benefit the next-generation electronics and photonics technologies.
Bio: Han Wang is an Assistant Professor in the Department of Electrical Engineering at University of Southern California. He received the B.A. degree with highest honors in electrical and information science from Cambridge University in 2008 and his PhD degree from Massachusetts Institute of Technology in 2013. From 2013 to 2014, he was with the Nanoscale Science and Technology group at IBM T. J. Watson Research Center in Yorktown Heights, NY. His research interests include the fundamental study and device technology of two-dimensional materials including black phosphorus, graphene, hBN, MoS2 etc., with emphasis on exploring both the fundamental understanding and their new applications in advanced electronics, mid- and far-infrared optoelectronics, energy efficient applications, and interaction with biological systems. His past research also includes GaN-based III-V HEMTs for high power millimeter-wave applications and Si power electronic devices. His work has been recognized with numerous awards including the NSF CAREER award, USC Zumberge Faculty Research Award 2015, the Roger A. Haken Best Paper Award in IEEE International Electron Device Meeting (IEDM) 2012, MIT Jin-Au Kong Best Doctoral Thesis Award 2013, and the Best Paper Award in International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH) 2010. Dr. Wang has authored or coauthored more than 60 publications in distinguished journals and conferences.
All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.