Metal and Semiconductor Nanocrystals for Quantum Devices

Sammanfattning: Aerosol technology was used to develop new methods for fabrication of size-selected, nanometer-sized particles of metals and semiconductors. Such particles were used to realize different types of quantum devices and nanometer-sized structures. The thesis contains an introduction, five papers on particle fabrication, and five papers on particle-based quantum devices. Size-selected gallium and indium particles were allowed to react with arsine, phosphine, and ammonia, resulting in crystalline particles of gallium arsenide and indium phosphide, between 8 and 50 nanometers in diameter. Gold particles were made by the evaporation/condensation method, and sintering and thermal charging were studied. Tungsten particles were made by thermal cracking of tungsten hexacarbonyl. Gold particles were alloyed with indium and gallium to make particles with tailored size and composition, and the particle structure and composition were studied. A method using electrostatic forces for placing particles during deposition was developed. Individual particles of gold and indium were used to make single electron tunneling devices. A single electron transistor working up to 200 K was made by contacting a 7 nanometer gold particle with 3 nanometer carbon nanotubes. Gold particles were used as seeds for growth of whiskers of III-V semiconductors with internal heterostructures. Tungsten particles were epitaxially embedded in gallium arsenide.