  The Seebeck coefficient in single and bilayer graphene sheets has been
observed to be modest due to the gapless characteristic of these structures. In
this work, we demonstrate that this coefficient is significantly high in
quasi-1D structures of bilayer armchair graphene nanoribbons (BL-AGNRs) thanks
to the open gaps induced by the quantum confinement effect. We show that the
Seebeck coefficient of BL-AGNRs is also classified into three groups 3p, 3p +
1, 3p + 2 as the energy gap. And for the semiconducting BL-AGNR of width of 12
dimer lines, the Seebeck coefficient is found as high as 707 uV/K and it
increases up to 857 uV/K under the impact of the vertical electric field. While
in the semimetallic structure of width of 14 dimer lines, the Seebeck
coefficient remarkably enhances 14 times from 40 uV/K to 555 uV/K. Moreover, it
unveils an appealing result as the Seebeck coefficient always increases with
the increase of the applied potential. Such BL-AGNRs appear to be very
promising for the applications of the next generation of both electronic and
thermoelectric devices applying electric gates.
