Metal-semiconductor-metal photodetectors on a GeSn-on-insulator platform for 2 m applications

• Main Authors: Son, Bongkwon, Lin, Yiding, Lee, Kwang Hong, Margetis, Joe, Kohen, David, Tolle, John, Tan, Chuan Seng
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering; Germanium-tin alloys, germanium-tin on insulator, metal-semiconductor-metal photodetector
• Online Access: https://hdl.handle.net/10356/156216
• Institution: Nanyang Technological University

In this work, the metal-semiconductor-metal photodetectors were demonstrated on the Ge0.91Sn0.09-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 the wavelength beyond 2,200 nm. The dark current density was measured to be 4.6 A/cm2 for GeSnOI waveguide-shaped photodetectors. The 3dB 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.