Ultrahigh responsivity of optically active, semicondUcting asymmetric nanochannel diodes

LLE Review, Volume 143 167 Introduction Room-temperature nanodevices based on quantum confinement and/or ballistic nonlinearities are intrinsic nanostructures, not simply scaled-down conventional circuitry, and are gaining wide-spread research attention. Among the nanodevices, one of the most popular is the asymmetric nanochannel diode (ANCD), also referred to as a self-switching diode (SSD), first proposed by Song et al.1 ANCD’s, contrary to conventional diodes, do not rely on energy-barrier concepts to achieve rectification, but rather their nonlinear current–voltage (I–V) characteristics result from the carrier transport in an asymmetric nanochannel. The ANCD planar geometry allows for a flexible design and easy integration as a multi-element sensor or with either optical nanoconcentrators or THz coupling antennas. Based on Monte Carlo (MC) simulations, ANCD’s are expected to be efficient THz generators,2 which have been demonstrated to be viable THz detectors.3