![]() Carbon nanotubes have been shown to have unique properties, stiffness and strength, higher than any other material. Iijima reported the first observation of carbon nanotubes. Nanocapsules and nanodevices may present new possibilities for drug delivery, gene therapy, and medical diagnostics. Surface properties, such as energy levels, electronic structure, and reactivity can be quite different from interior states, and give rise to quite different material properties. In nanomaterials, the small feature size ensures that many atoms, perhaps half or more in some cases, will be near the interfaces. Surfaces and interfaces are very important for nanomaterials, but in the case of bulk materials, a relatively small percentage of atoms will be at or near a surface or interface. In the past 10 years, nanomaterials with diameters in the range of 1-20 nm, have become a major interdisciplinary area of research interest and their extremely small feature size has the potential for wide-ranging industrial, biomedical, and electronic applications. In semiconductors, current can be carried either by the flow of electrons or by the flow of positively-charged holes in the electron structure of the material. In a metallic conductor, the current is carried by the flow of electrons. It is difficult to alter the resistivity through doping or external fields and the bandgap between the valence band and the conduction band is large. In the case of conductors, that have very low resistivities, the resistance is difficult to alter, and the highest occupied energy band is partially filled with electrons and the insulator has extremely high resistivities. The resistivities of the semiconductor can be altered by up to 10 orders of magnitude, by doping or external biases. In semiconductors, the highest occupied energy band, the valence band is completely filled with electrons and the empty next one is the conduction band. Introduction A semiconductor is a material that has an electrical conductivity between a conductor and an insulator. Organic Optoelectronic Materials and Devices 13. Research on Nano Optoelectronic Sensors and Photovoltaic Devices 12. Silicon Semiconductor Nanomaterials and Devices 11. Semiconductor Nanomaterials for Hydrogen Production 10. Application of Semiconductor Nanomaterials 9. Surface Modification of Nanocrystals and Interparticle Forces in Solution 7.5. Main Parameters Governing Solvothermal Reactions 7.4. Quasi One Dimensional (1D) Nanostructures 4.3. Zero Dimensional (0D) Nanostructures 4.2. Classifications of Semiconductor Nanostructures 4.1. Introductions to Nanoscience and Nanotechnology 3.
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