  Two-dimensional polyaniline monolayer (C3N) has been recently synthesized as
an indirect semiconductor with high electron mobility. In this research, with
combination of density functional theory and Green function formalism, we
investigate electrical and thermal properties of C3N sheet in details. It is
observed that a tensile strain along zigzag direction can induce a transition
from indirect to direct semiconductor, whereas the sheet transits from
semiconductor to metal under compressive strain. Thermoelectric efficiency of
unstretched C3N sheet is higher in p-doping and its maximum value is obtained
when the transport is along zigzag direction. A reduction in figure of merit is
found upon applying strain independent from its direction. To overcome the
reduction, we show that when the electrical transport and strain are
perpendicular to each other, thermoelectric efficiency of the C3N sheet can be
significantly increased dependent on the kind of strain (tensile or
compression). Results predict the potential application of C3N sheet in
thermoelectric and optoelectronic industry by strain engineering.
