Dark current reduction for photodetectors using cycling excitation process (CEP)
Abstract
We have recently demonstrated a new physical mechanism, cycling excitation process (CEP), for light detection. As a photodetector, the device has shown excellent performance in terms of sensitivity, gain, frequency response, efficiency, and scalability. Above all, the device has shown the ability to detect single photons at high speed. One key area that needs significant improvement is its dark current, which is 1000 to 10,000 times greater than the desired value. To address this critical problem, we propose a research project to answer the following two questions: (a) where the dark current come from and (b) how to find practical approaches to reduce its magnitude to meet the target value. We find the answer of the first question by analyzing data from temperature dependent dark current measurements. Our preliminary investigations point out that tunneling current is the dominant factor for the high dark current of CEP devices because of the thin (typically 30nm) gain medium and the high E-field. Hence our focus here will be to suppress electron and hole tunneling via direct (band-to-band) or indirect (band-to-local states) pathways. We will develop schemes to cut down all possible tunneling paths. In addition, any scheme that suppresses tunneling should not compromise other device performance such as quantum efficiency, CEP gain, frequency response, and sensitivity. By solving the dark current problem, we will be able to realize the full potential of the CEP detectors for a wide range of applications including imaging, sensing, and optical communications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 01, 2019
- Source ID
- W911NF1910530
Entities
People
- Yu-Hwa Lo
Organizations
- Army Contracting Command
- Defense Advanced Research Projects Agency
- University of California, San Diego