Low temperature growth of heavy boron-doped hydrogenated Ge epilayers and its application in Ge/Si photodetectors

•Heavy boron-doped hydrogenated Ge epilayers are grown by electron cyclotron resonance chemical vapor deposition, which have highly conductive.•We modulate the hydrogen flow rate to improve the Ge epilayers crystal quality.•Boron-doped Ge epilayers grown on Si substrate at low temperature (220°C).