Ohio State University ECE Distinguished Seminar Series
Sponsored by the IEEE EDS/Photonics Columbus Chapter under its Distinguished Lecturer Program

Tuesday, May 17, 2011
1:30 PM in 260 Dreese Laboratories

The Infrared Retina: Bioinspired Sensing for Using Nanoscale Superlattices and Quantum Dots

Sanjay Krishna
Professor and Assoc. Director Center for High Technology Materials
University of New Mexico

Abstract: Infrared detectors operating in the 3-20 m are important due to three main reasons. Firstly, the atmosphere is transparent in the two bands referred to as mid wave infrared (MWIR, 3-5 m) and long wave infrared (8-12 m) making it possible to see through fog and smoke under poor visibility conditions. Secondly, a lot of chemical species have characteristic absorption features in this wavelength range making these detectors vital for remote sensing and stand off detection. Finally, there is blackbody emission from living objects at these wavelengths making it possible to use them for “night vision” and thermography applications such as surveillance and medical diagnostics. Presently, we are in, what is referred to as, the third generation of infrared detectors. In this colloquium, Prof. Krishna will make predictions about the fourth generation of infrared detectors. Using the concept of a bio-inspired infrared retina, he will make a case for an enhanced functionality in the pixel. The key idea is to engineer the pixel such that it not only has the ability to sense multimodal data such as color, polarization, dynamic range and phase but also the intelligence to transmit a reduced data set to the central processing unit. He will use two material systems, which are emerging as promising infrared detector technologies as prototypes to highlight this approach. These are (i) InAs/InGaAs self assembled quantum dots in well (DWELL) hetereostructure and InAs/(In,Ga)Sb strain layer superlattices (SLS) Detectors. Various approaches for realizing the infrared retina will be discussed. In addition to the applications of infrared imaging for defense application, Sanjay highlight the role of infrared imaging in non-invasive medical diagnostics. In particular, he will highlight some work on using infrared imaging in the early detection of skin cancer.

Bio: Sanjay Krishna is the Associate Director of the Center for High Technology Materials and a Professor in the Department of Electrical and Computer Engineering at the University of New Mexico. Sanjay received his M.S. from IIT, Madras, MS in Electrical Engineering in 1999 and PhD in Applied Physics in 2001 from the University of Michigan. He joined UNM as a tenure track faculty member in 2001. His present research interests include growth, fabrication and characterization of nanoscale quantum dots and type II InAs/InGaSb based SLS for mid infrared detectors. Sanjay received the Gold Medal from IIT, Madras, Ralph Powe Junior Faculty Award, IEEE Outstanding Engineering Award, ECE Department Outstanding Researcher Award, School of Engineering Jr. Faculty Teaching Excellence Award, NCMR-DIA Chief Scientist Award for Excellence, the NAMBE Young Investigator Award, and the IEEE-NTC and SPIE Early Career Achievement Award. He was recently awarded the UNM Teacher of the Year and the UNM Regents Lecturer award. Sanjay has more than 200 peer-reviewed journal articles (h-index=24), two book chapters and five issued patents and has recently been elected as an SPIE Fellow.

Host: Paul R. Berger

No RSVP required

ECE Distinguished Seminar Series
Sponsored by the IEEE EDS/Photonics Chapter under its Distinguished Lecturer Program

Suman Datta
Monkowsky Associate Professor
The Pennsylvania State University

Thursday, April 22, 2010
1:30 PM, 260 Dreese Laboratory

Abstract: Since 1926 it is well accepted that the continuous nonzero nature of solutions to Schrodinger’s wave equation used to represent electrons, even in classically forbidden regions of negative kinetic energy, allows for a finite and tunable probability of tunneling from one classically allowed region to another (for example band to band tunneling in a semiconductor). We are investigating a novel transistor architecture based on such tunneling mechanism as a step towards demonstrating steep switching transistors for energy efficient logic and embedded memory applications. In this seminar, we will address the following topics regarding the tunnel transistor architecture: a) the choice of appropriate materials to tune the transfer characteristics over a specified gate swing b) the characteristic screening lengths in these device essential for scaling dc) an effective way to estimate the switching speed of such devices, d) digital circuit design methodologies utilizing tunnel transistors, and, finally, e) the importance of nonequilibrium carrier dynamics on the device terminal characteristics. We will present the experimental tunnel transistor results till date and show that inter-band tunnel transistor is a promising architecture for future low power computing and storage applications.

Bio: Suman Datta is the Monkowsky Associate Professor in the Department of Electrical Engineering at the Penn State University with a joint appointment in the Penn State Materials Research Institute. Suman received his Bachelors in Electrical Engineering from the Indian Institute of Technology, Kanpur, India, in 1995 and his Ph.D. in Electrical & Computer Engineering from the University of Cincinnati, USA, in 1999. As a member of the Logic Technology Development and Components Research Group at Intel Corporation, from 1999 to 2007, he was instrumental in the demonstration of the world’s first enhancement and depletion mode indium antimonide based quantum-well transistors operating at room temperature with record power-delay product, the first experimental demonstration of the effect of metal gate plasmon screening and channel strain engineering in mitigating the remote soft optical phonon induced mobility degradation in high-k/metal-gate CMOS transistors and, finally, the investigation of the transport properties and the electrostatic robustness in non-planar “Tri-Gate Transistors” for extreme scalability. Since Fall of 2007 he has been at Penn State University exploring new materials, novel nanofabrication techniques and non-classical device structures for CMOS “enhancement” as well as “replacement” for future energy efficient computing applications. He has over 68 archival refereed journal and conference publications and holds 97 US patents.