Electronic transport properties of molecular devices

✍ Scribed by A. Pecchia; L. Latessa; A. Di Carlo; P. Lugli; Th. Neihaus

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 248 KB
• Volume: 19
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(03)00300-x

✦ Synopsis

Density functional theory calculations combined with non-equilibrium Green's function technique have been used to compute electronic transport in organic molecules. In our approach the system Hamiltonian is obtained by means of a self-consistent density-functional tight-binding (DFTB) method. This approach allows a ÿrst-principle treatment of systems comprising a large number of atoms. The implementation of the non-equilibrium Green's function technique on the DFTB code allows us to perform computations of the electronic transport properties of organic and inorganic molecular-scale devices. The non-equilibrium Green's functions are used to compute the electronic density self-consistently with the open-boundary conditions naturally encountered in transport problems and the boundary conditions imposed by the potentials at the contacts. The Hartree potential of the density-functional Hamiltonian is obtained by solving the three-dimensional Poisson's equation involving the non-equilibrium charge density. The method has been applied to study the transport properties of a variety of molecular systems. It also allows for self-consistent computations of the atomic forces and to perform molecular dynamics simulations which are used to investigate the role of thermal uctuations in coherent transport through organic molecules.