Whole industries currently rely on bulk-grown crystals of a variety of materials. These industries range from information technology, based on the ubiquitous silicon, through radiofrequency applications, using gallium arsenide, etc.,'to telecommunications and lighting, based on III-V compounds, to infrared imaging, based on cadmium mercury telluride, and to high-energy physics and medical imaging using scintillator materials. These materials are used either in the active mode, as for silicon, or in the passive mode where the bulk-grown material is used as a substrate on which to deposit a wide range of binary, ternary, quaternary, etc., compounds by several epitaxial growth processes.