In a method for electrically doping a semiconducting material, a layer of germanium is formed having a germanium layer thickness, while in situ incorporating phosphorus dopant atoms at a concentration of at least about 5×1018 cm−3 through the thickness of the germanium layer during formation of the germanium layer. Additional phosphorus dopant atoms are ex situ incorporated through the thickness of the germanium layer, after formation of the germanium layer, to produce through the germanium layer thickness a total phosphorus dopant concentration of at least about 2×1019 cm−3.