Threading dislocation densities in semiconductor crystals: a geometric approach

摘要

In this letter, we introduce a geometric model to explain the origin of theobserved shallow levels in semiconductors threaded by a dislocation density. Weshow that a uniform distribution of screw dislocations acts as an effectiveuniform magnetic field which yields bound states for a spin-half quantumparticle, even in the presence of a repulsive Coulomb-like potential. Thisintroduces energy levels within the band gap, increasing the carrierconcentration in the region threaded by the dislocation density and addingadditional recombination paths other than the near band-edge recombination.