This book presents invited reviews and original short notes of recent results obtained in studies concerning the fabrication and application of nanostructures, which hold great promise for the new generation of electronic and optoelectronic devices. Governing exciting and relatively new topics such as fast-progressing nanoelectronics and optoelectronics, molecular electronics and spintronics, nanophotonics, nanosensorics and nanobiology as well as nanotechnology and quantum processing of information, this book gives readers a more complete understanding of the practical uses of nanotechnology and nanostructures.