Guidelines for Overcoming the Practical Limitations for the Fabrication of THz Sources with GaN Planar Gunn Diodes

Gunn oscillations are expected to appear in GaN at high electric fields due to its negative differential mobility, but they have never been observed experimentally due to the large voltages to be applied. We propose a way to avoid such practical problems by fabricating planar Gunn diodes with shaped nanochannels which allow to reduce the total DC current and focus the electric field in regions far from the contacts.