Current flow through a dislocation wall in a bicrystal or grain boundary, in a semiconductor, was considered. It was known that the broken bonds along the dislocations made up acceptor levels which were offset from the bottom of the conductance band. The electron population depended upon the bulk donor concentration and the dislocation spacing. At sufficiently low donor concentrations, electrons which were captured at dislocation acceptors produced a periodic 2D-lattice having 2 comparable periods which were of the order of the reciprocal of the square root of the 2D-density of captured electrons. The charges of those electrons resulted in the formation of a dislocation potential barrier whose height was periodically modulated in the wall plane. The electron current preferred to flow along the paths of lowest barrier height. That is, through the saddle-points of the 3D-potential relief in the dislocation-wall plane. At low enough temperatures, this led to a separation of the electron current into numerous branches. Provided that both 2D-lattice periods of the captured charges were small in comparison with the electron mean free path, these narrow short branches constituted filamentary 1D-conductors exhibiting ballistic transport. Effects which were associated with the 1D-conductance quantization defined the entire system resistance, and could be observed experimentally. In particular, an exponential temperature dependence of the whole system resistance disappeared.

Branching of Electron Current and Quantum Effects in Two-Dimensional Dislocation Barrier of n-Type Semiconductor. E.Z.Meilikhov, R.M.Farzetdinova: Physica E, 1998, 3[4], 190-7