High-Performance GeSn Photodetector Covering All Telecommunication Bands
Nan Wang, Chunlai Xue, Fengshuo Wan, Yue Zhao, Guoyin Xu, Zhi Liu, Jun Zheng, Yuhua Zuo, Buwen Cheng, Qiming Wang
Abstract
We report the design and fabrication of a high-speed GeSn normal-incidence p-i-n photodetector. To realize high-speed detection in all telecommunication bands, we optimize the Sn content in the absorption layer, the absorption-layer thickness, and the device size. The responsivity of the 18-μm-diameter device at 1550 nm reaches 0.32 A/W with an extended cutoff wavelength of 1700 nm and a 3-dB bandwidth as high as 28 GHz under -3 V bias, clear open eye diagrams are also obtained under zero bias at 1630 nm. All the results indicate that the device has a significant potential for applications in Si-based optical telecommunication in all telecommunication bands.