Si-Based GeSn Photodetectors toward Mid-Infrared Imaging Applications

Huong Tran, Thach Pham, Joe Margetis, Yiyin Zhou, Wei Dou, Perry C. Grant, Joshua M. Grant, Sattar Al-Kabi, Greg Sun, Richard A. Soref, John Tolle, Yong Hang Zhang, Wei Du, Baohua Li, Mansour Mortazavi, Shui Qing Yu

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


The GeSn detector offers high-performance Si-based infrared photodetectors with complementary metal-oxide-semiconductor (CMOS) technique compatibility. In this work, we report a comprehensive study of Si-based GeSn mid-infrared photodetectors, which includes the demonstration of a set of photoconductors with Sn compositions ranging from 10.5% to 22.3%, showing the cutoff wavelength has been extended to 3.65 μm. The maximum D∗ of 1.1 × 1010 cm·Hz1/2·W-1 measured at 77 K is comparable to that of commercial extended-InGaAs detectors. We also report the development of a surface passivation technique on photodiodes based on an in-depth analysis of a dark current mechanism, effectively reducing the dark current. Moreover, mid-infrared images were obtained using GeSn photodetectors, showing the comparable image quality with that acquired by using commercial PbSe detectors. This work is a major step toward Si-based mid-infrared photodetectors for imaging applications.

Original languageEnglish (US)
Pages (from-to)2807-2815
Number of pages9
JournalACS Photonics
Issue number11
StatePublished - Nov 20 2019


  • GeSn photodetector
  • high Sn composition
  • imaging
  • mid-infrared
  • surface passivation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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