2015 Volume 56 Issue 9 Pages 1362-1364
We have grown un-doped and transition metal (V, Cr, Mn, Fe, Co, Ni, Cu)-doped Ge bulk single crystals using the vertical gradient solidification method. The electrical resistivities of V, Ni, Co, and Fe-doped Ge crystals significantly increased, 104∼105 times, between 5 and 100 K, which were 100 times larger than that of the commercial Ge resistance temperature device (RTD). The large variation of electrical resistance at low temperature arises from decreased carrier density and mobility at low temperature. The mobility reduction at low temperature might be caused by ionized impurity scattering.