Princeton University

School of Engineering & Applied Science

Recent progresses in quantum well infrared photodetectors

Speaker: 
K. K. Choi, U.S. Army Research Laboratory
Location: 
EQUAD J401
Date/Time: 
Monday, November 2, 2015 - 3:00pm

Abstract: In this talk, I will give an overview of the quantum well infrared photodetector (QWIP) technology and its recent development. In particular, we have developed a finite element three-dimensional electromagnetic model for quantum efficiency computation. It is applicable to any arbitrary detector geometry and materials with isotropic or anisotropic absorption properties. Using this model, we can accurately account for all open literature experimental results that we have investigated, which include those from quantum well infrared photodetectors (QWIPs), strained layer superlattices, and GaAs solar cells. We applied the model to design more efficient QWIPs and observed experimental quantum efficiency (QE) as high as 71%. Therefore, we are now able to fully determine the optical properties of QWIPs through material and structural modeling. In this talk, we will compare the modeled and the observed quantum efficiency and show some infrared videos.

Bio: Dr. K. K. Choi received the Ph.D. in Physics from Yale University in 1984. He worked at Princeton University and AT&T Bell Laboratories before joining Army Research Laboratory in 1988. At ARL, he researches on new detector material and architecture and produces high resolution imaging arrays for military, civilian, and scientific applications. Dr. Choi is the Senior Research Scientist for Physical Sciences at ARL.