  We investigate electron and phonon transport through edge disordered zigzag
graphene nanoribbons based on the same methodological tool of nonequilibrium
Green functions. We show that edge disorder dramatically reduces phonon thermal
transport while being only weakly detrimental to electronic conduction. The
behavior of the electronic and phononic elastic mean free paths points to the
possibility of realizing an electron-crystal coexisting with a phonon-glass.
The calculated thermoelectric figure of merit (ZT) values qualify zigzag
graphene nanoribbons as a very promising material for thermoelectric
applications.
