Metal-Semiconductor-Metal Photodetectors on a GeSn-on-Insulator Platform for 2 µm Applications

• Published in: IEEE photonics journal Vol. 14; no. 3; pp. 1 - 6
• Main Authors: Son, Bongkwon, Lin, Yiding, Lee, Kwang Hong, Margetis, Joe, Kohen, David, Tolle, John, Tan, Chuan Seng
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.06.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Dark current; Germanium; Germanium-tin alloys; germanium-tin on insulator; Intermetallic compounds; metal-semiconductor-metal photodetector; Metals; Optical waveguides; Photodetectors; Photometers; Plasma temperature; Silicon; Strain; Waveguides; Wavelengths
• ISSN: 1943-0655; 1943-0655; 1943-0647
• DOI: 10.1109/JPHOT.2022.3164943

In this work, the metal-semiconductor-metal photodetectors were demonstrated on the Ge 0.91 Sn 0.09 -on-insulator (GeSnOI) platform. The responsivity was 0.24 and 0.06 A/W at wavelengths of 1,600 and 2,003 nm, respectively. Through a systematic study, it is revealed that the photodetectors can potentially detect wavelength beyond 2,200 nm. The dark current density was measured to be 4.6 A/cm 2 for GeSnOI waveguide-shaped photodetectors. The 3 dB bandwidth was observed to be 1.26 and 0.81 GHz at 1,550 and 2,000 nm wavelengths, respectively. This work opens up an opportunity for low-cost 2 µm wavelength photodetection on the GeSn/Ge interface-free GeSnOI platform.