Open AccessTwo-micron-wavelength germanium-tin photodiodes with low dark current and gigahertz bandwidth
Author(s) -
Yuan Dong,
Wei Wang,
Shengqiang Xu,
Dian Lei,
Xiao Gong,
Xin Guo,
Hong Wang,
Shuh-Ying Lee,
Wan-Khai Loke,
S. F. Yoon,
Yee-Chia Yeo
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.015818
Subject(s) - dark current , photodetector , photodiode , germanium , optoelectronics , optics , materials science , biasing , wavelength , silicon , bandwidth (computing) , quantum efficiency , tin , physics , voltage , telecommunications , quantum mechanics , computer science , metallurgy
We report the demonstration of a germanium-tin (Ge 0.9 Sn 0.1 ) multiple-quantum-well p-i-n photodiode on silicon (Si) substrate for 2 μm-wavelength light detection. Characterization of the photodetector in both direct current (DC) and radio frequency (RF) regimes was performed. At the bias voltage of -1 V, a dark current density of 0.031 A/cm 2 is realized at room-temperature, which is among the lowest reported values for Ge 1- xSnx-on-Si p-i-n photodiodes. In addition, for the first time, a 3 dB bandwidth (f3dB) of around 1.2 GHz is achieved in Ge 1- xSnx photodetectors operating at 2 μm. It is anticipated that further device optimization would extend the f3dB to above 10 GHz.