Hydrodynamic instability of one-dimensional electron flow in semiconductors

The hydrodynamic instability of one-dimensional flow of electrons in an ungated semiconductor driven by a voltage difference is studied. The governing transport and electrostatic equations are linearized about the steady flow, and the eigenspectrum of perturbations is calculated. The carrier flow is found to be unstable under certain circumstances through oscillations that manifest themselves as planar waves. Higher voltages lead to greater rates of growths of the instability. The frequencies of oscillation are found to be of the order of terahertz, making the phenomenon suitable for consideration as a solid-state radiative source at this frequency range. (C) 2007 American Institute of Physics.