Towards controlled dislocations
Crystallographic defects or irregularities (known as dislocations) are often found within crystalline materials. Two main types of dislocation exist: edge and screw type. However, dislocations found in real materials tend to be a mix of these two types, resulting in a complex atomic arrangement not found in bulk crystals. The study of these dislocations in semiconductors is probably as old as the science of semiconductors itself, and the technological importance of dislocations can hardly be overstated. From their roles in the way crystals form to their effects on a material's mechanical, thermal and opto-electronic properties, dislocation and defects govern many aspects of a material's behaviour. Therefore, it is of great scientific interest to identify and study these structures, and understand their impact on the properties of technologically important materials and devices, such as solar cells, photon detectors and similar semiconductor devices.