A high-performance Ge/GeSi multi-quantum wells photodetector on a Ge-buffered Si substrate

• wang he, kong zhenzhen, Xinguang Tan, SU JIALE, Junhao Du, Hongxiao Lin, li ben, wang yijie, ZIWEI ZHOU, MIAO YUANHAO, Zhao xuewei, Hu qin, and Henry Radamson
• received 02/14/2024; accepted 04/01/2024; posted 04/03/2024; Doc. ID 521237
• Abstract: This work demonstrates a high-performance photodetector with a 4-cycle Ge/Ge0.84Si0.16 multi-quantum wells (MQWs) structure grown by reduced pressure chemical vapor deposition techniques on a Ge-buffered Si (100) substrate. At -1V bias, the dark current density of the fabricated PIN mesa devices is as low as 3 mA/cm2, and the optical responsivities are 0.51 and 0.17 A/W at 1310 and 1550 nm, respectively, corresponding to the cutoff wavelength of 1620nm. At the same time, the device has good high-power performance and continuous repeatable light response. On the other hand, the temperature coefficient of resistance (TCR)of the device is as high as -5.18%/K, surpassing all commercial thermal detectors. These results indicate that the CMOS-compatible and low-cost Ge/Ge0.84Si0.16 multilayer structure is promising for short-wave infrared and uncooled infrared imaging.