Charge transport in stacking metal and metal‐free phthalocyanine iodides. Effects of packing, dopants, external electric field, central metals, core modification, and substitutions

Abstract

The charge-transport properties of the one-dimensional stacking metal phthalocyanine iodides (M(Pc)I, M = Fe, Co, Ni, Cu) and metal-free phthalocyanine iodide (H2(Pc)I) have been theoretically investigated. On the basis of the tight-binding approximation and two-state theory, both the site-energy corrected energy splitting in dimer and Fock-matrix-based methods are used to calculate the transfer integral. The intermolecular motions, including interplanar translation, rotation, slip, and tilt, exert remarkable impacts on the transfer integral. The order/disorder of the dopant stack and the long-range electrostatic interactions are also demonstrated to be crucial factors for modulation of charge-transport properties. The transfer integral undergoes slight changes under an applied electric field along the stacking direction in the range of 10(6)-10(7) V cm(-1). The change of central metals in MPc has little effect on the transfer integrals, but significantly affects the reorganization energies. The extension of the pi-conjugation in macrocyclic ligand brings about considerable influence on the transfer integrals. Peripheral substitutions by animo, hydroxyl, and methyl lead to deviations from planarity of macromolecular rings, and hence affect the valence bands significantly.

Charge transport and prototypical optical absorptions in functionalized zinc phthalocyanine compounds: A density functional study

“…We find that the optimized geometry has D 4h symmetry in all XZnPc compounds similar to those reported earlier in the cases of ZnPc and F 16 ZnPc. () The Zn‐N1 bond length in ZnPc at the described computational level is found to be 2.024 Å, which is almost same as the previous theoretical value reported by Liao et al but is 0.04 Å less than the experimental value. () Functionalization of the outer benzene rings with groups such as F, Cl, Br, I, CN has a very little effect on the bond distance between the tetra coordinated central Zn atom and the nitrogen (N) atoms of 4 pyrrole rings of XZnPc molecules.…”

“…Evolution of transfer integral and the charge carrier mobility of XZnPcs were studied using the dimer approach in terms of different molecular orientations. () In this paper, we considered 3 different orientations, namely, (1) translation of the co‐facial molecule along the stacking axis (2) shifting of adjacent molecules along the long molecular axis, and (3) rotation of the molecule about the stacking axis. To calculate transfer integrals, we implemented DFT methodology, which has been tested to provide reliable results in many cases.…”

“…To calculate transfer integrals, we implemented DFT methodology, which has been tested to provide reliable results in many cases. ()…”

“…Over the last several years, metal phthalocyanines (MPcs) have attracted a considerable amount of attentions due to their broad applications in the fields of organic semiconductors (OSCs), organic photovoltaic cells (OPVCs), organic solar cells, optical data storage, photosensitizers, gas sensing, spintronic applications, photoconducting agents, and so on. () In addition, these materials, due to their chemical and thermal stabilities, are also used as dyes in chemical industries. () However, the process of observation of these MPcs through transmission electron microscope (TEM) causes structural damages to the compounds due to the interaction with electron irradiation.…”

Long-range corrected DFT calculations of charge-transfer integrals in model metal-free phthalocyanine complexes

“…An inherent issue of practical computations of charge–transfer integrals represents the choice of an approach to solve the Schrödinger equation. Currently, the DFT framework is commonly used to model charge transport in organic materials [3, 8–14]. Certain exchange–correlation potentials are recognized to predict accurately geometries of molecules and shapes of molecular orbitals.…”