Infrared Detectors with Quantum Dots and Type II InAs/GaSb Strained Layer Superlattices

Sanjay Krishna 

University of New Mexico (UNM), 1313 Goddard SE, Albuquerque 87106, United States


There is an increasing need for mid infrared (3-25㎛) detectors and focal plane arrays for applications ranging from night vision surveillance to non-invasive medical diagnostics. This presentation will be focused on the fabrication of focal plane arrays using two material systems, which are emerging as promising technologies for mid infrared sensors. These are (i) InAs/InGaAs self assembled quantum dots in well (DWELL) Detectors and InAs/(In,Ga)Sb strain layer superlattices (SLS) Detectors

In the DWELL heterostructure, InAs quantum dots are placed in a thin InGaAs quantum well that is in turn placed in a GaAs matrix. Three-color DWELL detectors, operating at 78K, with spectral response in the MWIR (λp1 ~ 4㎛), LWIR (λp2 ~ 8㎛) and VLWIR (λp3~ 23㎛) regime have been fabricated in our group. Recently, we have fabricated the first long wave infrared quantum dot focal plane array (320x256 pixels). Images from this FPA along with the details of our research will be discussed in the presentation. The second material system we are investigating is the type II InAs/InGaSb superlattice for MWIR/LWIR detection. We have recently fabricated a high performance InAs/GaSb SLS detector with a 5㎛ cut-off operating at room temperature and 320x 256 FPA based on a novel nBn design. This will be discussed in the presentation.

Acknowledgements: I wish to acknowledge my collaborators (Dr. Cardimona’s group at AFRL, Prof. Perera’s group at Georgia State University, Prof. Painter’s group at Caltech, Dr. Toni Taylor’s group at Los Alamos National Laboratory and researchers from ARL) and co-workers ( Prof. L.R. Dawson, Prof. A. Stintz, , Dr. S.J. Lee, Dr. E. Plis, Dr. Y.D. Sharma, H.S. Kim, J. Shao, D. Ramirez, A. Barve, N.W. Bernstein, S. Myers, A. Khoshakhlagh, J. Montoya, M. Kutty, E. Jang and R. Shenoi). Work supported by AFRL, ARL, ARO, MDA, KOSEF-GRL, DARPA, and NSF




Sanjay Krishna is the Associate Director of the Center for High Technology Materials and an Associate Professor of Electrical and Computer Engineering at the Center for High Technology Materials at University of New Mexico. Sanjay received his Masters in Physics from the Indian Institute of Technology, Madras in 1996, MS in Electrical Engineering in 1999 and PhD in Applied Physics in 2001 from the University of Michigan, Ann Arbor. He joined the University of New Mexico as a tenure track faculty member in 2001. His present research interests include growth, fabrication and characterization of self-assembled quantum dots and type_II InAs/InGaSb based strain layer superlattices for mid infrared detectors. Dr. Krishna received the Gold Medal from IIT, Madras in 1996. He received the best student paper award at the 16th NAMBE Conference in Banff in 1999, the 2002 Ralph E Powe Junior Faculty Award from Oak Ridge Associated Universities, the 2003 IEEE Outstanding Engineering Award, 2004 Outstanding Researcher Award from the ECE Department, the 2005 School of Engineering Junior Faculty Teaching Excellence Award, 2007 NCMR-DIA Chief Scientist Award for Excellence, the 2007 NAMBE Young Investigator Award and the 2008 SPIE and IEEE-NTC Early Career Achievement Awards.  Dr. Krishna has authored/co-authored more than 60 peer-reviewed journal articles, over 40 conference presentations, two book chapters and has two issued and six pending paten

Presentation: Invited oral at E-MRS Fall Meeting 2009, Symposium D, by Sanjay Krishna
See On-line Journal of E-MRS Fall Meeting 2009

Submitted: 2009-05-10 21:51
Revised:   2009-08-13 17:25