We present a theoretical treatment of surface–field THz generation in semiconductors, which explains the power enhancement observed when a magnetic field is applied. Our model consists of two parts: a Monte Carlo simulation of the dynamics of carriers generated by a subpicosecond optical pulse, and a calculation of the resulting THz radiation emitted through the semiconductor surface. The magne...

Electron irradiation of solids produces a backemission of secondary electrons (energies between 0 and 50 eV) and re ected primaries (energies between 50 eV and that of the incident beam). For insulators, it is shown that an externally applied positive electric eld penetrating into the solid material, energizes electrons generated by the primary irradiation and enables them to travel back to the...

The authors report the field emission FE properties of individual ZnO nanowire field emitters. ZnO nanowire field emitter directly grown on a Pt tip showed a much better field emission current delivery than the attached nanowire emitters due to better contact properties. The emission current and field emission microscopy pattern of the ZnO nanowire are strongly influenced by adsorbates. After t...