Physics and Technology of Antimonide Based Infrared Detectors
by Prof. Sanjay Krishna (Professor and George R Smith Chair in Engineering, Department of Electrical & Computer Engineering, Ohio State University, Columbus OH)
Thursday, December 12, 2019 from to (Asia/Kolkata)
Mid infrared imaging (3-25mm) has been an important technological tool for the past 60 years since the first report of infrared detectors in 1950s. There has been a dramatic progress in the development of antimonide based detectors and low power electronic devices 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 investigates antimonide based materials for infrared detectors and focal plane arrays. Our three research thrusts include (a) Antimonide based infrared materials and devices, (b) Next generation focal plane arrays (FPAs) and (c) Novel applications of infrared imaging and sensing. (https://kind.engineering.osu.edu/). In this talk, I will describe some of the material science and device physics of the antimonide systems. The use of “unipolar barrier engineering” to realize high performance infrared detectors and focal plane arrays will be discussed. I will define the current status of the technology and what are the current scientific and technical challenges. We will discuss some new ideas such as use of superlattices for single carrier impact ionization to realize low noise avalanche photodiodes and use of dielectric resonators to increase the signal to noise ratio of infrared detectors. I will also explore the possibility of realizing next generation 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.