Ge/Si (001) photodetector for near infrared light

We report on Ge Schottky diodes epitaxially grown on Si(001) exhibiting a good responsivity in the near-infrared up to 1.55 mu m. The Ge layers were grown by UHV chemical vapor deposition. It was found that the photocurrent increases upon increasing the reverse bias, reaching a maximum responsivity of 0.12 A/W at 1.3 mu m for 4 V bias. The leakage current density at the saturation voltage is 1 nA/mu m(2)