High responsitivity near infrared Ge photodetectors integrated on Si

The authors have fabricated and tested heterojunction Ge/Si photodetectors based on pure Ge epitaxially grown on Si (001) using a two-step UHV-CVD process followed by cyclic thermal annealing. The detectors exhibit responsivities as high as 550mA/W at 1.32 mu m and 250mA/W at 1.55 mu m and response limes shorter than 850ps