PFI:AIR - TT: Hot Electron Nanophotonic UV/IR CMOS Quanta Image Sensors and Photodetectors

Dartmouth College, Hanover NH

Investigators

Abstract

This PFI: AIR Technology Translation project focuses on translating a novel nanophotonic ultraviolet(UV)/infrared(IR) photodetector structure onto existing silicon-based image sensors, such as those used in cell phone cameras, to greatly extend their vision well beyond the visible light.  These Nanophotonic UV/IR Quanta Image Sensors (UV/IR QIS) are important because they can be seamlessly integrated with the cameras in our cell phones and other devices to "see" things that are outside of the visible spectrum and thus invisible to human eyes. This feature opens the door for low-cost, large-arrayed image sensors to enter the billion-dollar market of UV/IR imaging, including powerline inspection, vehicle driver vision enhancement, biomedical imaging, and environmental monitoring.  The project will result in a proof-of-concept prototype of nanophotonic UV/IR QIS with the following unique features: (1) ultrahigh sensitivity allowing single photon detection; (2) compatibility with existing image sensor array fabrication technology; and (3) ease of miniaturization. These features provide the following advantages when compared to the leading competing technologies: (1) Significantly extended detection spectral range well beyond human vision compared to existing silicon image sensors; (2) Higher sensitivity and larger pixel array than existing GaN (Gallium Nitride)-based UV detectors and InGaAs (Indium Gallium Arsenic)-based IR detectors; and (3) Drastic cost and weight reduction (up to 10-100x) compared to existing solar-blind UV (based on GaN) and short wave IR cameras (based on InGaAs). This project addresses the following technology gap(s) through the following tasks over the course of the project: (A) Optimized device design integrating hot-electron internal photoemission mechanism with existing silicon QIS device structure; (B) Choosing adequate oxide and metallic nanostructures compatible with silicon nanoelectronics for spectral extension into the IR regime (i.e. metal/oxide interfacial barrier engineering); (C) Device fabrication for overall integration. By successfully demonstrating this proof-of-concept prototype, the team will develop techniques to address all these issues. In addition, personnel involved in this project, especially the graduate students, will receive innovation, entrepreneurship, and technology translation experiences through the development of market-entry prototypes and potentially founding their own start-up company. The project engages LaXense, Inc. to expedite the commercialization of the nanophotonic IR photodetectors in this technology translation effort by providing a market-entry application in their existing photonics platform.