Book excerpt: This book comprehensively covers the areas of materials growth, characterisation and descriptions for the new devices in siliconheterostructure material systems. In recent years, the development of powerful epitaxial growth techniques such as molecular beam epitaxy (MBE), ultra-high vacuum chemical vapour deposition (UHVCVD) and other low temperature epitaxy techniques has given rise to a new area of research of bandgap engineering in silicon-based materials. This has paved the way not only for heterojunction bipolar and field effect transistors, but also for other fascinating novel quantum devices. This book provides an excellent introduction and valuable references for postgraduate students and research scientists.