DNA-based thermoelectric devices: A theoretical prospective

The thermoelectric performance of PolyG-PolyC and PolyA-PolyT double-stranded chains connected between organic contacts at different temperatures is theoretically studied on the basis of an effective model Hamiltonian. The obtained analytical expressions reveal the existence of important resonance effects leading to a significant enhancement of the Seebeck coefficient depending on the Fermi level position. High thermoelectric power factors, up to $P=(1.5–3)\times {10}^{-3}\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-2}$, are obtained close to the resonance energy. These values suggest that significantly high values of the thermoelectric figure of merit may be attained for synthetic DNA samples at room temperature. The possibility of combining $p$-type and $n$-type synthetic DNA chains in the design of a nanoscale Peltier cell is discussed, taking into account both contact and environmental effects.

Figure 1

(Color online) Sketch illustrating the basic features of a nanoscale DNA-based Peltier cell. A polyA-polyT (polyG-polyC) oligonucleotide, playing the role of $n$-type, left ($p$-type, right) semiconductor legs, is connected to organic wires (light boxes) deposited onto ceramic heat sinks (dark boxes).

Figure 2

(Color online) Room temperature dependence of the Seebeck coefficient as a function of the Fermi level energy for a G-C (solid curve) and A-T (dashed curve) Watson-Crick BP. Inset: The Landauer conductance as a function of the Fermi level energy for the same BPs.

Figure 3

(Color online) Seebeck coefficient as a function of the Fermi level energy for a polyG-polyC (solid curve) and a polyApolyT (dashed curve) oligomer with $N=5\mathrm{BPs}$. The vertical dashed line separates the energy regions exhibiting $n$-type and $p$-type thermopower, respectively. Inset: The Seebeck coefficient as a function of the Fermi level energy for an A-T Watson-Crick BP (solid line) is compared to that correspoding to a polyA-polyT oligomer with $N=5$ (dashed line).

Figure 4

(Color online) Landauer conductance as a function of the Fermi level energy for polyA-polyT oligomers with $N=2$ (solid curve), 3 (dasehd curve), and 5 (short dashed curve). Inset: Landauer conductance as a function of the Fermi level energy for a polyG-polyC oligomer with $N=5$.

Figure 5

(Color online) Room temperature thermoelectric power factor as a function of the Fermi level energy for G-C (solid curve) and A-T (dashed curve) Watson-Crick BPs. Inset: Room temperature thermoelectric power factor as a function of the Fermi level energy for a polyG-polyC oligomer with $N=5$.

Figure 6

(Color online) Seebeck coefficient as a function of the Fermi level energy for a polyG-polyC oligomer with $N=5\mathrm{BPs}$ and $\gamma =4.5$ (solid curve), 4.0 (dashed curve), and $3.0\mathrm{eV}$ (dotted curve) with $\tau =t_M=0.15\mathrm{eV}$, and ${\epsilon }_M=0\mathrm{eV}$. Inset: Landauer conductance as a function of the Fermi level energy for the same samples shown in the main frame.

Figure 7

(Color online) Transmission coefficient as a function of the Fermi level energy, determined from Eq. (15) including contact effects, for a polyG-polyC oligomer with $N=10\mathrm{BPs}$ and $\gamma =4.5$ (solid curve), 4.0 (dashed curve), and $3.0\mathrm{eV}$ (dotted curve) with $\tau =t_M=0.15\mathrm{eV}$, and ${\epsilon }_M=0\mathrm{eV}$.