Wide band gap self-switching nanodevices for THz applications at room temperature

A self-switching diode (SSD) is based on an asymmetric nanochannel. The SSD is fabricated by tailoring the boundary of a narrow semiconductor channel to break its symmetry. An applied voltage V not only changes the potential profile along the channel direction but also either widens or narrows the effective channel width, depending on its sign. This results in a strong nonlinear current-voltage I-V characteristic, resembling that of a conventional diode which could be used for detection. Besides, the special geometry of SSDs benefits the onset of Gunn oscillations since the electrical field is well focused at the cathode side of the channel and the electron concentration is increased by the side field effect, so that the classical criteria for Gunn oscillations are more easily reached. The main advantage of using GaN is that it will provide much higher power than traditional GaAs Gunn diodes at very high frequency (in excess of 300 GHz) due to its high saturation velocity, high breakdown field and the possibility of high temperature operation. Here, detection measurements will be presented.