Traveling charge domains and direct millimeter-wave generation

Dipole instabilities and MMW oscillation

The group develops semiconductor approaches to direct millimeter-wave and terahertz generation based on traveling charge-domain instabilities in III-nitride materials. This research combines analytic transport theory with stochastic solution of the Boltzmann transport equation and device-level simulation.

A central challenge is not merely whether a mature charge domain can propagate, but whether one can be nucleated in the first place. Recent work by the group identifies diffusion as the microscopic process that inhibits nucleation and shows why conventional GaN Gunn-diode geometries are especially demanding. A planar AlGaN/GaN triode, closely related to a HEMT, creates a localized high-field nucleation site and supports self-sustaining Gunn-mode oscillation in stochastic Boltzmann transport simulations.