Effect of DNA bases on the thermoelectric performance in graphene nanoribbons

The thermoelectric transport properties of four kinds of DNA bases sandwiched between two zigzag-edge graphene nanoribbon electrodes are investigated by first-principles calculation. The modulation of quantum interference, molecular length, and molecular torsion on thermoelectric transport properties are studied. It is found that the thermopower and efficiency can be obviously enhanced in the guanine and electrode coupling geometry that manifests a quantum interference effect. A decrease of thermopower with a number of DNA bases has been found, while the efficiencies have a different trend with the increase of the number of different molecules. In addition, the thermopower and efficiency also can be considerably enhanced by the twisting angle between the molecule and graphene electrodes.