Antimonide Materials and Devices for 4th Generation Infrared Detectors and Imagers

Wednesday, September 23, 2015

12:00 pm | Hudson 208

Presenter

Dr. Sanjay Krishna , Director, Center for High Technology Materials Professor and Regents’ Lecturer, Department of Electrical and Computer Engineering

Infrared imaging (3-25μm) has been an important technological tool for the past sixty years since the first report of infrared detectors in 1950s. There has been a dramatic progress in the development of infrared antimonide based detectors in the past decade with new materials like InAsSb, InAs/GaSb superlattices and InAs/InAsSb superlattices demonstrating very good performance. One of the unique aspects of the 6.1A family of semiconductors (InAs, GaSb and AlSb) is the ability to engineer the bandstructure to obtain designer band-offsets. Our group (www.krishnairlab.com) has been involved with the vision of the 4th generation of infrared detectors and is one of two university laboratories in the country that can undertake “Design to Camera” research and realize focal plane arrays.

My talk will revolve around three research themes.

The first theme involves the fundamental investigation into the material science and device physics of the antimonide systems. I will describe some of the challenges in these systems including the identification of defects that limit the performance of the detector. The use of “unipolar barrier engineering” to realize high performance infrared detectors and focal plane arrays will be discussed.

The second theme will involve the vision of the 4th Gen infrared imaging systems. Using the concept of a bio-inspired infrared retina, I 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. The design and demonstration of meta-infrared detectors will be discussed.

In the final theme, I will describe the role of infrared imaging in bio-medical diagnostics. In particular, I will highlight some work on using infrared imaging in the early detection of skin cancer and for detection of flow in cerebral shunts. Using dynamic thermal imaging on over 100 human subjects, a sensitivity >95% and specificity >83% has been demonstrated. Commercialization of this technology will also be discussed.

Sanjay Krishna is the Director of the Center for High Technology Materials and Professor and Regents 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. He currently heads a group of 15 researchers involved with the development of next generation infrared imagers. 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, IEEE-NTC and SPIE Early Career Achievement Award and the ISCS Young Scientist 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=40), two book chapters and seven issued patents. He is the co-founder and CTO of Skinfrared, a UNM start-up involved with the use of IR imaging for non-invasive medical diagnostics including early detection of skin cancer. He is a fellow of IEEE and SPIE.