Electric Field modulated electronic, thermoelectric and transport properties of 2Dtetragonal silicene and its nanoribbons.

Using both first principles and analytical approaches, we investigate the effect of the transverse electric field on the electrical,
thermoelectric, optical, and transport properties of a buckled tetragonal silicene (TS) structure. The transverse electric field
causes a band opening in both Dirac points in the BZ of the TS structure. The gap opening rises in proportion to the applied
field strength. However, a sufficiently strong electric field converts the system into a metallic one. A comparable band
opening is seen in the TS nanoribbons. When an electric field is applied to the system, it behaves as semiconducting, which
improves its thermoelectric properties. The optical response of the structures is very asymmetric. Large values of imaginary
and real components of the dielectric function are seen. The absorption frequency lies in the UV region. Plasma frequencies
are identified and are red-shifted with the applied field. Current-voltage characteristics of the symmetric type nanoribbons
show oscillation in current whereas voltage rectifying capability of anti-symmetric type nanoribbons under transverse electric
field is interesting.