The electrical conductivity of thin LiI films was measured  in situ, during growth, as a function of the film thickness and the temperature. It was found that films which were grown at 27C exhibited an enhancement of ionic conduction of about 40 times the bulk value. This occurred in a region which extended to about 100nm away from the interface. This enhanced conduction was unstable, and decreased (according to a log-time dependence) during annealing at the growth temperature. The activation energy for conduction was 0.47eV. This was approximately equal to the value for extrinsic conduction in the bulk iodide. Films which were grown at 100C exhibited an enhancement near to the interface, and an almost linear increase in conductivity with thickness (after an initial nucleation stage). The conductivity of these films was stable at, and above, the growth temperature and was associated with an activation energy of 0.75eV. This was comparable to the value for intrinsic LiI. The use of X-ray diffractometry showed that all of the LiI films were cubic. Films which were grown near to room temperature had a marked (002) orientation, while those which were grown at high temperatures were of (111) orientation, with a mosaic spread of less than 0.4. The data showed conclusively that there was no enhancement due to space-charge layer formation at the film/substrate interface. The data were instead consistent with a model which assumed that conduction enhancement was caused by the overlapping of the strain fields of dislocations that formed during growth

D.Lubben, F.A.Modine: Journal of Applied Physics, 1996, 80[9], 5150-7