Electrical conductivity of germanium with dislocation grids

Samples of n-type germanium with a donor concentration N-d = 2.4 x 10(16) c m(-3) are plastically deformed to a degree of strain equal to 18-40% to det ect static conduction by electrons trapped on dislocations in a system of d islocation grids. In samples with 20%< delta<31%, which retain an electroni c type of conductivity, the conductivity for T<8 K, which is weakly tempera ture-dependent, is associated with conduction by electrons trapped on dislo cations. The nonmonotonic dependence of the conductivity at 4.2 K on the de gree of strain as the latter increases from 18% to 40% attests to the exist ence of an energy gap between the donor and acceptor dislocation states in strongly plastically deformed germanium. (C) 1999 American Institute of Phy sics. [S1063-7761(99)01101-4].