A high-responsivity photodetector absent metal-germanium direct contact

Yi Zhang, Shuyu Yang, Yisu Yang, Michael Gould, Noam Ophir, Andy Eu-Jin Lim, Guo-Qiang Lo, Peter Magill, Keren Bergman, Tom Baehr-Jones, Michael Hochberg
2014 Optics Express  
We report a Ge-on-Si photodetector without doped Ge or Gemetal contacts. Despite the simplified fabrication process, the device shows a responsivity of 1.14 A/W at −4 V reverse bias and 1.44 A/W at −12V, at 1550 nm wavelength. Dark current is less than 1µA under both bias conditions. We also demonstrate open eye diagrams at 40Gb/s.
doi:10.1364/oe.22.011367 pmid:24921833 fatcat:psj2o5s325blbbhh5fcamhknay