DNA-based thermoelectric devices: A theoretical prospective

Abstract

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 = ͑1.5-3͒ ϫ 10 −3 W m −1 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.

Electrical conductance in duplex DNA: Helical effects and low-frequency vibrational coupling

“…8 The hydrogen bonding between complementary bases is then described as an additional hopping term perpendicular to the DNA stack, [9][10][11][12][13] and appropriate on-site energies and hopping parameters for the backbone must be included as well. [14][15][16] The resulting models are essentially a planar projection ͑two dimensions͒ of the DNA structure with its double helix unwound, so that the successive bp's are lined up face to face along the strand. This geometrical constraint optimizes the -orbital coupling between neighboring bases, hence overestimating charge transport efficiency.…”

“…Following previous works, the electronic degrees of freedom of a double-stranded DNA ͑including sugar-phosphate and environmental effects͒ are described in terms of a renormalized, one-dimensional effective Hamiltonian given by 15,16 …”

π−πorbital resonance in twisting duplex DNA: Dynamical phyllotaxis and electronic structure effects

“…Thus, effective model Hamiltonians can be expressed as the sum of two main contributions H = H e + H l , where H e describes the charge dynamics over the -stacked electronic system and H l describes the duplex DNA dynamics. The electronic degrees of freedom of a double-stranded DNA ͑including sugar-phosphate and environmental effects͒ are described in terms of the effective Hamiltonian, 32,42,43 …”

“…Equation ͑1͒ describes the charge propagation through a DNA duplex in terms of an equivalent one-dimensional lattice, where the renormalized "atoms" correspond to complementary pairs in the original DNA molecule whose on-site energies ˜n͑E͒ ͕␣͑E͒ , ␤͑E͖͒ depend on the charge energy E and enclose the quantum description of the Watson-Crick bp energetics through the expressions 42,43 …”

“…The high energy region of the spectra, located around the energy value E Ӎ 6.46 eV, is related to the sugar-phosphate DNA subsystem, whereas the low energy region, centered around the value E Ӎ −0.49 eV, is related to the nucleobase DNA subsystem. 43,51 In the equilibrium configuration the electronic spectrum is composed of two relatively broad bands. Due to the lattice coupling effects, both bands are split in a number of narrower subbands.…”