  Simple estimations show that the thermoelectric readout in graphene radiation
detectors can be extremely effective even for graphene with modest
charge-carrier mobility ~1000 cm^2/(Vs). The detector responsivity depends
mostly on the residual charge-carrier density and split-gate spacing and can
reach competitive values of ~10^3 - 10^4 V/W at room temperature. The optimum
characteristics depend on a trade-off between the responsivity and the total
device resistance. Finding out the key parameters and their roles allows for
simple detectors and their arrays, with high responsivity and sufficiently low
resistance matching that of the radiation-receiving antenna structures.
