SEMINAR: "Polarization-Engineered Nitride Heterostructure Devices: Tunneling & Doping," by Debdeep J
January 29 @ 3:30 PM - 4:30 PM - PHYS 203
Abstract: III-V nitride semiconductor heterostructures exhibit strong built-in spontaneous and piezoelectric polarization fields - a fact that is well known by now. It has been used to good effect in electronic devices such as HEMTs, but cause problems in optical devices due to Stark-effect induced reduction of oscillator strengths. By using Molecular Beam Epitaxial growth, our group has recently a) Used polarization for high-performance AlN/GaN HEMTs well suited to scaling, b) Used polarization to enable Zener tunneling in p-n junctions, and c) Used polarization-induced p-type doping in N-Face graded heterostructures and demonstrated UV LEDs. In my talk, I will present these new developments in logical flow, and show how the wide-bandgaps and the colossal polarization fields give us the tools to do heterostructure bandgap engineering that goes beyond tradiational III-V and Si-based semiconductors.
Biographical Sketch: Debdeep Jena received the B. Tech. degree with a major in Electrical Engineering and a minor in Physics from the Indian Institute of Technology (IIT) Kanpur in 1998, and the Ph.D. degree in Electrical and Computer Engineering at the University of California, Santa Barbara (UCSB) in 2003. He joined the faculty of the department of Electrical Engineering at the University of Notre Dame in 2003. His research and teaching interests are in the MBE growth and device applications of quantum semiconductor heterostructures (currently III- V nitride semiconductors), investigation of charge transport in nanostructured semiconducting materials such as graphene, nanowires and nanocrystals, and their device applications, and in the theory of charge, heat, and spin transport in nanomaterials. He has received two best student paper awards in 2000 and 2002 for his Ph.D. dissertation research, the NSF CAREER award in 2007, and an undergraduate teaching award in 2009.