Abstract
Amorphous silicon films have been modified by the implantation of Au or Si ions. The d.c. conductivity, measured between 300 and 15 K, was found to exhibit hopping exponents m which increase with decreasing temperature. Depending on the varied defect densities, m ranges between the limits of 1/4 and 1. These results can be explained by variable-range-hopping theory, if a Coulomb correlation term is included.