GROUP IV PHOTODETECTOR OPERATED AT MID-INFRARED REGION
Abstract
Group IV photodetectors (PDs) are vital to integrating Si-based readout circuit at a low cost and high efficiency. Driven by the need for photodetection beyond Si (visible region) for use in the infrared region, group IV materials are employed, including Ge-on-Si wafer PDs and the recently developed GeSn-on-Si (or Ge) wafer. However, several factors affect the photodetection capability of these heterostructured PDs, limiting their performance. In this project, two new structures are provided for high-performance PDs operating in the infrared region. (We focus on the two key characteristics of PD, detectivity and spectra response in the discussion.) The first type of PD is a foundary-compatible planar p-i-n photo diode fabricated on a thin film. The results show that its detectivity is comparable to that of a commercial Ge-based bulk single crystal PDs at 1550 nm. Here, we consider the other characteristic of the detector’s responsivity (R) and a new approach is provided. A high R compared to Ge PDs is expected. The second type of PD is a novel structure built on a two-dimensional material of graphene placed on a semiconductor thin film. The primary results show that the photoresponse of the GeSn thin film is amplified by an order of magnitude with a value of a few amperes per Watt. These results suggest that this is a promising approach for resolving key issues in heterostructured PDs. A further investigation on other characteristics will be performed, and expect better performance than the Ge detector.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 11, 2021
- Source ID
- FA23862014082
Entities
People
- Hung Hsiang Cheng
Organizations
- Air Force Office of Scientific Research
- National Taiwan University
- United States Air Force