Thermoelectric power and electrical conductance of DNA based molecular junctions

The thermoelectric performance of short oligonucleotides connected in between metallic contacts at different temperatures is theoretically studied on the basis of a model Hamiltonian. The obtained analytical expressions reveal the existence of important resonance effects leading to a significant enhancement of both the electrical conductance and thermoelectric power in the case of trimer codons. On the other hand, dimerization effects lead to a conductance degradation accompanied by a slight thermopower enhancement in the case of dinucleotides. The potential of metal-nucleobase-metal junctions for thermoelectric applications is discussed by considering different design parameters, including the Fermi level position and the molecule-lead coupling strength value.