A Broad Spectrum (SWIR/MIR/FIR) System for Characterization of Cycling Excitation Process (CEP) Detectors
Abstract
We propose to acquire a broad spectrum detector characterization system that covers SWIR/MIR/FIR spectrum to investigate the physical and device properties of detectors using the physical mechanism of cycling excitation process (CEP). The CEP detector research is currently supported by the Office of Naval Research under Dr. Kevin Leonard.The proposed system will have the capabilities of measuring the quantum efficiency, gain, speed, sensitivity, detectivity, frequency dependent noise characteristics of CEP detectors designed to operate over a broad wavelength range from 1000nm to 15m. The system will also have the capability of producing single-pixel image over this spectral range.The SWIR/MIR/FIR detector characterization system consists of multiple light sources covering the full spectral range, imaging camera and alignment optics to direct the light to the detector area, beam control mechanism to control the irradiation area to the object for single-pixel image formation, probe station and microscope to make detector contact at the die level without packaging, and electronics for measurement of dark current, photocurrent, frequency dependentnoise, sensitivity and speed. To our best knowledge, there is not a single equipment vendor that sells such a system with all the desired features and functions covering such broad spectral range. Therefore, we will acquire light sources from one vendor, optics from another, and electronics from the other. The graduate students will put the parts together to set up such a system. We also foresee the need to control the temperature of the device when we measure its MIR and FIR characteristics for certain designs of CEP detectors. Therefore, we plan to set up the proposed system next to an existing cryochamber in our laboratory. The cryochamber has a device probe station, electric feedthroughs and optical windows so that the CEP detectors can also be characterized at cryogenic temperature with the proposed system when low temperaturemeasurements are needed.We propose to set up a CEP detector characterization system for SWIR/MIR/FIR wavelengths because CEP detectors have shown highly promising properties at visible wavelength, including high gain under low bias, ultralow noise, large (> 2THz) gain-bandwidth product, and single photon sensitivity. These properties are particularly attractive to DoD applications in the areas of imaging, sensing, and communication. One significant finding with CEP detectors is that the gainmedium can be made of disordered material such as amorphous silicon. Disordered materials have been considered to be unsuitable for high performance detectors because they contain a large number of defects and have low carrier mobility. The principle of cycling excitation process (CEP) fundamentally changes the conventional notion of material quality as those defects actually play positive roles in the CEP process and contribute to high gain and sensitivity. Above all, amorphous silicon and other disordered materials can be formed on different light absorption materials without the constraints of lattice match, offering great flexibility in detector spectralrange and process compatibility. A system that can be used to characterize CEP detectors at SWIR/MIR/FIR wavelength can serve a variety of applications of DoDs interest.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 17, 2020
- Source ID
- N000142012661
Entities
People
- Yuhwa Lo
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego