The capability to shape condensed matter, and specifically semiconductors, at the nanometer scale provides the researchers with a unique tool to tailor the physical properties of different materials. In this talk, we focus on two types of nanostructures featuring highly anisotropic electronic and morphological properties: nanowires (NWs) and rolled-up nanotubes (NTs). NWs are filamentary crystals –with diameter of few hundreds of nm or less, and several microns in length– fabricated in a scalable, flexible and well-controlled manner via a vapor–liquid–solid growth mechanism. III-V compounds (e.g., GaAs), III-nitrides (e.g., GaN), oxides (e.g., ZnO), and elemental semiconductors (e.g., Si) may be grown in the NW form. NWs are the smallest dimension structures that allow optical guiding and electrical contacting simultaneously. The large surface to volume ratio of NWs enhances their interaction with the environment, turning them into optimal chemical and biological sensors. Furthermore, NW anisotropic geometry makes their optical and electrical properties dramatically dependent on their orientation. Synthesis, main properties and applications of NWs will be reviewed. Rolled-up NTs are fabricated from strained semiconductor layer systems grown by molecular beam epitaxy. The strain is built up by growing semiconductor materials with a larger lattice constant on top of a material with a smaller lattice constant. By selective wet-chemically etching a sacrificial layer below the strained layers the incorporated strain bends up the layer system and leads to the self-rolling of a nanotube. NTs could act as nanopipelines for fluid transportation and generation of nanodroplets or nanobubbles. They also can be used as optical cavities, whose resonance modes can be effectively coupled with quantum dots. Examples regarding NT applications will be presented. Finally, potential perspectives of these advanced functional materials for high-energy physics will be discussed.
