Two-dimensional (2D) materials exhibit diverse electronic properties, ranging from metallic graphene and semiconducting transition metal dichalcogenides such as molybdenum disulphide, to insulating hexagonal boron nitride. In this talk, I will first address the physics of light-graphene interaction within the single-electron framework, followed by a discussion of light excitation of collective oscillations of the carriers, i.e., plasmons in graphene. I will focus on the unique graphene plasmonic properties arising from its “massless” carriers. Then I will briefly cover the advantages and disadvantages of semiconducting transition metal dichalcogenides in optoelectronics and electronics if compared with graphene. Finally I will present a few promising future research directions using recently rediscovered black phosphorus, which serendipitously bridges the zero-gap graphene and the relatively large-bandgap transition metal dichalcogenides such as molybdenum disulfide (MoS2).
Fengnian Xia received the B.E. degree with highest honor in electronics engineering from Tsinghua University, Beijing, China and Ph.D. degrees in electrical engineering from Princeton University, Princeton, NJ, USA. He joined IBM Thomas J. Watson research center in Yorktown Heights, NY, USA as a postdoc in 2005, and was a Research Staff Member before he started at Yale University in September 2013. Currently he is the Barton L. Weller associate professor in engineering and science at Department of Electrical Engineering. He currently explores the light-matter interaction and quantum transport in low-dimensional materials and also identifies their potential applications in computing, flexible electronics, imaging, optical communications, and energy harvesting.
Professor Xia’s honors include the National Science Foundation CAREER award (2016), the Office of Naval Research Young Investigator Award (2015), the IBM Pat Goldberg Memorial Best Paper Award (2014), the TR35 Award, MIT Technology Review’s Top Young Innovators under 35 (2011), the IBM Corporate Award, that corporation’s highest technical honor (2012), and the designation of the Weller Junior Professorship in Engineering and Science by Yale President in October 2015.
