ECE Seminar with Saptarshi Das

4:00 pm on Thursday, February 6, 2014
Photonics Center, 8 Saint Mary’s St., Room 339
2-D Electronics with Transition Metal Dichalcogenides: Progress and Prospect With Dr. Saptarshi Das Postdoctoral Research Scientist Purdue University Faculty Host: Anna Swan Refreshments will be served outside Room 339 at 3:45 p.m. Abstract: Low dimensional systems, by the virtue of their novel material properties and excellent electrostatic integrity, provide immense opportunities not only to explore fundamental physics but also to solve critical technological problems. One dimensional nanotubes, quasi one dimensional nanowires, two dimensional atomistically thin layered materials like graphene, hexagonal boron nitride and more recently, the rich family of transition metal di-chalcogenides (TMDs) comprising of MoS2, WSe2, MoSe2 and many more are prime examples of such low dimensional systems. What makes the TMDs unique in this list is the fact that, in addition to their ultra-thin body, the d-orbital electrons of the transition metal atoms play an important role in determining the band structures of the TMDs, which are assumed to be responsible for their extreme sensitivity to external forces like temperature, pressure, strain, light and charge. In my talk, I will first discuss how to connect these two dimensional ultra-thin TMDs to the “outside” world through ideal three dimensional metal contacts in order to capitalize on their ultimate potential. Then, I will provide experimental evidence that strongly suggests the feasibility of aggressive channel length scaling of field effect transistors (FET) based on TMDs beyond the 10nm CMOS technology node. I will also demonstrate Schottky barrier tunneling phenomenon in back gated MoS2 FETs and band to band tunneling phenomenon in partially top gated WSe2 FETs, which will facilitate the implementation of TMDs for ultra-low power electronics. And finally, I will show the effect of temperature, pressure, strain and light on the transport properties of the TMDs which can potentially shift the paradigm of conventional electronics. About the Speaker: I received my bachelor degree in Electronics and Telecommunication Engineering from Jadavpur University, India, in 2003. I joined Purdue University in 2007 and finished my doctorate degree in the area of Micro and Nano Technology from the department of Electrical and Computer Engineering in May 2013. Currently, I am jointly affiliated with the Center for Nanoscale Materials at the Argonne National Laboratory and with the Birck Nanotechnology Center at Purdue University as a Postdoctoral Research Scientist. I have worked in the Carbon Technology group at IBM T. J. Watson Research Center in 2009 and in the 22nm System and Technology group at IBM East Fishkill in 2011 as a summer intern. I also received the IBM Ph.D. fellowship for 2011-12. My research focuses on exploring the device physics of low dimensional systems like nanotubes, nanowires, graphene and more recently, the two dimensional layered Transition Metal Dichalcogenides for low power and high speed electronics applications.