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Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope
Published on: May 28, 2016
Insulator-to-Semiconductor-to-Conductor Phase-Like Transition of DNA Chains
C A Plazas1, K M Fonseca-Romero2, R R Rey-González2
1Universidad Libre, Facultad de Ingeniería, Bogotá D.C., 111071, Colombia.
Abstract:
Using a tight-binding model, we study the transport of charge carriers through DNA molecular wires. In double-stranded DNA chains, according to Chargaff's rules, only Adenine-Thymine (AT) and Cytosine-Guanine (CG) pairs are allowed. In our model, a decimation procedure allows us to represent each pair of bases by a single site with one localized electronic state. We consider chains of different lengths with only AT (CG) sites, and ordered and disordered chains with both types of sites. Disordered chains may include short range correlation. Additionally, hydration is considered in the form of a change of the site energy. We find a conductor-to-semiconductor-to-insulator transition as a function of the three effects taken into account: chain size, intrinsic disorder of CG and AT pairs, and hydration. This model predicts that an appropriate choice of chain size and concentration of AT pairs can be used to tailor the electrical behavior of DNA strands.
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