Ferromagnetic instability in a doped band gap semiconductor FeGa3

Impurity band conduction in a high temperature ferromagnetic semiconductor.

The band structure of a prototypical dilute magnetic semiconductor (DMS), Ga1-xMnxAs, is studied across the phase diagram via infrared and optical spectroscopy. We prove that the Fermi energy (EF) resides in a Mn-induced impurity band (IB). Specifically the changes in the frequency dependent optical conductivity [sigma1(omega)] with carrier density are only consistent with EF lying in an IB. Fu...

Vertically aligned nanostructures based on Na-doped ZnO nanorods for wide band gap semiconductor memory applications.

Vertically aligned undoped ZnO nanotips, nanotubes and nanorods were synthesized on the top facets of Na-doped ZnO nanorods without catalytic assistance under different growth times in a chemical vapor deposition system. The growth mechanism is discussed. The Na-doped nanorods were grown on a ZnO seed layer on Si. The p-type conductivity of the Na-doped nanorods was studied by temperature-depen...

Josephson Current in a Ferromagnetic Semiconductor/Semiconductor/Ferromagnetic Semiconductor Junction with Superconducting Contacts

Intervalence-band THz laser in selectively-doped semiconductor structure

Monte Carlo simulation of carrier dynamics and far-infrared absorption in a selectively-doped p-type multilayer Ge structure with vertical transport was performed to test a novel terahertz laser concept. The design exploits the known mechanism of THz amplification on intersubband transitions in p-Ge, but with spatial separation of light hole accumulation regions from doped regions, which allows...

Photonic Band Gap Materials: A Semiconductor for Light

Light in certain engineered dielectric microstructures can flow in a way similar to electrical currents in semiconductor chips. These microstructures represent a new frontier in the field of optics. They provide a foundation for the development of novel micro-photonic devices and the integration of such devices into an optical microchip. Glossary: Photonics: the science of moulding the flow of ...