Using a two-dimensional ensemble Monte Carlo (EMC) method, electronic nanometer devices with different parameters are studied in detail. Calculation results show that at nanoscale the electric properties of interface inside the devices play an important role in determining the working properties of the devices. By properly arranging device structures, surface charges originated from device fabrication can be exploited to produce a predetermined electric potential in the devices. Based on this fact, two structures that can lead to an asymmetric potential along their nanochannel are proposed for designing strong nonlinear devices. Further studies indicate that Ratchet effect brought by the asymmetric potential results in diode-like current-voltage characteristics of the devices. Through optimizing device parameters, zero threshold voltage can be achieved, which is desired for detecting applications. Moreover, since the devices are at nanoscale, simulation results reveal that used as rectifiers the working frequencies can be up to a few THz.

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