The 23rd ICPS continues the tradition of the preceding conferences. Advances in bulk semiconductors and defect and impurity related problems are reviewed. A key role is played by semiconductor structures with reduced dimensionality, as heterostructures, superlattices, quantum wires, and dots. Special emphasis is given to growth-related problems, and new semiconducting materials (inorganic as well as organic) and novel devices will be highlighted. The proceedings provide an exhaustive overview on the most recent achievements in semiconductor physics.