High doping regimes of B implanted Ge have been accurately characterized combining Hall effect technique and nuclear reaction analysis. Preamorphized Ge was implanted with B at 35 keV (spanning the 0.25–25× 10 20 B∕ cm 3 concentration range) and recrystallized by solid phase epitaxy at 360 C⁠. The Hall scattering factor and the maximum concentration of active B resulted r H= 1.21 and∼ 5.7× 10 20 B∕ cm 3⁠, respectively. The room-temperature carrier mobility was accurately measured, decreasing from∼ 300 to 50 cm 2∕ V s in the investigated dopant density, and a fitting empirical law is given. These results allow reliable evaluation for Ge application in future microelectronic devices.