There is an increasing need for silicon-compatible high bandwidth extended-short wave infrared (e-SWIR) photodetectors (PDs) to implement cost-effective and scalable optoelectronic devices. These systems are quintessential to address several technological bottlenecks in detection and ranging, surveillance, ultrafast spectroscopy, and imaging. In fact, current e-SWIR high bandwidth PDs are predominantly made of III-V compound semiconductors and thus are costly and suffer a limited integration on silicon besides a low responsivity at wavelengths exceeding $2.3 \,μ$m. To circumvent these challenges, Ge$_{1-x}$Sn$_{x}$ semiconductors have been proposed as building blocks for silicon-integrated high-speed e-SWIR devices. Herein, this study demonstrates a vertical all-GeSn PIN PDs consisting of p-Ge$_{0.92}$Sn$_{0.08}$/i-Ge$_{0.91}$Sn$_{0.09}$/n-Ge$_{0.89}$Sn$_{0.11}$ and p-Ge$_{0.91}$Sn$_{0.09}$/i-Ge$_{0.88}$Sn$_{0.12}$/n-Ge$_{0.87}$Sn$_{0.13}$ heterostructures grown on silicon following a step-graded temperature-controlled epitaxy protocol. The performance of these PDs was investigated as a function of the device diameter in the $10-30 \,μ$m range. The developed PD devices yield a high bandwidth of 12.4 GHz at a bias of 5V for a device diameter of $10 \,μ$m. Moreover, these devices show a high responsivity of 0.24 A/W, a low noise, and a $2.8 \,μ$m cutoff wavelength thus covering the whole e-SWIR range.
Systematic study of high performance GeSn photodiodes with thick absorber for SWIR and extended SWIR detection
University of Arkansas（阿肯色大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Naval Surface Warfare Center（海军水面武器中心）；Air Force Research Laboratory（空军研究实验室）
Study of GeSn Selective Area Growth with Demonstration of SWIR Light Detection
Arkansas Materials Institute, University of Arkansas（阿肯萨斯材料研究所，阿肯色大学）；Department of Electrical Engineering and Computer Science, University of Arkansas（电气与计算机工程系，阿肯色大学）；Material Science and Engineering Program, University of Arkansas（材料科学与工程项目，阿肯色大学）；Lincoln Laboratory, Massachusetts Institute of Technology（林肯实验室，麻省理工学院）；Thayer School of Engineering, Dartmouth College（斯怀瑟工程学院，达特茅斯学院）；Arktonics, LLC（阿科托尼克斯有限责任公司）；Department of Physics, University of Arkansas（物理系，阿肯色大学）
