Polar-optical-phonon induced nonlinearity at semiconductor interfaces

The dynamical behavior of GaAs-based Schottky-diode interfaces near the pol ar-optical-phonon (POP) resonance frequency is addressed. The manifestation of a tetrahertz-regime coupling mechanism between the temporal evolution o f the diode barrier and POPs is revealed. Specifically, POPs are shown to p erturb the spatial dependence of the displacement field within the depletio n region and strongly enhance the nonlinearity associated with diode curren t. This resonance coupling emerges in the unscreened barrier region and lea ds to dramatic nonlinear effects on both the resistive (i.e., emission part icle transport) and the reactive (displacement transport) physics. This str ong and highly localized frequency-space phenomenon has broad implications to all polarsemiconductor-based heterostructure devices that utilize nonlin ear electron transport effects. (C) 1999 American Institute of Physics. [S0 003-6951(99)04341-7].