Molecular orbital analysis of frontier orbitals for molecular electronics: a case study of unimolecular rectifier and photovoltaic cell

Abstract

Recently, unimolecular devices have attracted significant attention as a 'post-silicon technology' to enable the fabrication of future nanoscale electronic devices. In this paper, we describe a candidate molecule for a rectifier function using porphyrin polymer and a photovoltaic cell using fullerene-based supramolecule. We have investigated the geometric and electronic structure of these organic molecules using an ab initio quantum mechanical calculation. These results for the porphyrin polymers show that the localization of the unoccupied orbital state on the acceptor moiety mostly depends on their structures. The calculated results for the electronic structure of a naphthalocyanine -fullerene supramolecule manifest that the HOMO's were localized on the donor sub-unit and the LUMO's were localized on the acceptor sub-unit. q

Probing the Effect of Applied Electric Field in Charge Density Distribution and Electrostatic Properties of Au Substituted Saturated Polycyclic Hydrocarbon Molecular Nanowires via Quantum Chemical and Charge Density Study

“…Recently, Li et al [1] found a considerable reduction of the HOMO-LUMO gap on increasing the length of molecular chain constituting the molecular wires. In the present study, the saturated aromatic polycyclic hydrocarbon molecules have been considered as molecular nanowires, which contains polycyclic bridges [2] connected to polyacetylene chain as shown in Fig.6.1.…”

“…The Laplacian of electron density has been constructed from second partial derivative and it is a measure of the curvature of the function in three dimensions. Also,2 ρ bcp (r) of the molecule bear the chemical significance of bond topological theory of molecular structure. For the applied field, Laplacian of electron density of all bonds almost vary slightly.…”