This fifth volume in the series covering the latest results in the field includes abstracts of papers which appeared within the approximate period of mid-2001 to mid-2002. The scope of this coverage again includes, in addition to traditional semiconductors, the increasingly important carbide, nitride and silicide semiconductors. Semiconducting oxides are not covered, as information on these can be found in the "Defects and Diffusion in Ceramics" series. However, the invited papers this time deal exclusively with staple semiconducting materials: including work on interstitial clusters, intrinsic point defects, and {113} defects in silicon; defect states in InAs quantum dots and defect generation at ZnSe/GaAs interfaces. There are also papers treating a wide range of general themes: such as tracer diffusion in a concentrated lattice gas, defect luminescence in layered chalcogenide semiconductors, defect formation after laser thermal processing, redistribution of point defects in an inhomogeneous temperature field, and very general mathematical techniques for determining basic diffusion parameters.