  We evaluate the proposed resonant terahertz (THz) detectors on the base of
field-effect transistors (FETs) with split gates, electrically induced lateral
p-n junctions, uniform graphene layer (GL) or perforated (in the p-n junction
depletion region) graphene layer (PGL) channel. The perforated depletion region
forms an array of the nanoconstions or nanoribbons creating the barriers for
the holes and electrons. The operation of the GL-FET- and PGL-FET detectors is
associated with the rectification of the ac current across the lateral p-n
junction enhanced by the excitation of bound plasmonic oscillations in in the
p- and n-sections of the channel. Using the developed device model, we find the
GL-FET and PGL-FET-detectors characteristics. These detectors can exhibit very
high voltage responsivity at the THz radiation frequencies close to the
frequencies of the plasmonic resonances. These frequencies can be effectively
voltage tuned. We show that in PL-FET-detectors the dominant mechanism of the
current rectification is due to the tunneling nonlinearity, whereas in
PGL-FET-detector the current rectification is primarily associated with the
thermionic processes. Due to much lower p-n junction conductance in the
PGL-FET-detectors, their resonant response can be substantially more pronounced
than in the GL-FET-detectors corresponding to fairly high detector
responsivity.
