Electrical conductivity of germanium with dislocation grids

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