Terahertz detection using nanorectifiers

We report on the lowerature detection of free-space radiation at 1.5 THz using a unipolar nanodiode, known as the self-switching diode (SSD), coupled with a spiral microantenna. The SSD, based on an asymmetric nanochannel, has a diode-like characteristic that can be utilized in rectifying high-frequency electrical signals. The truly planar structure of the SSD not only provides intrinsically low parasitic capacitance that enables rectification at ultrahigh speed, but also allows the fabrication of a large SSD array in parallel without the need for interconnection layers. The extrinsic voltage responsivity of the SSD-based detector achieved was {\sim}{\rm 15.6}~{\rm V}/{\rm W}, but the estimated intrinsic voltage responsivity was {\sim}{\rm 45}~{\rm kV}/{\rm W}. © 2013 IEEE.