Synthesis, characterization, self-assembly and non-ohmic Schottky barrier diode behaviors of two iron(III) based semiconductors with theoretical insight

Two mononuclear iron(III) complexes, [Fe(L-1)(N-3)] and [Fe(L-2)(N-3)], {H2L1 = N,N'-bis(3-methoxysalicylidene)diethylenetriamine and H2L2 = N,N'-bis(3-ethoxysalicylidene)diethylenetriamine} have been synthesized and characterized by elemental, spectral and X-ray crystallographic studies. Structural features have been examined in detail that reveal the formation of interesting supramolecular networks generated through weak non-covalent interactions. The current-voltage characteristic curves for an Al/complex Schottky-barrier diode (SBD) exhibit non-ohmic behavior. Important parameters like ideality factor, barrier height and series resistance are measured with the help of thermionic emission (TE) theory. Space-charge-limited current (SCLC) theory is employed to evaluate the charge transport parameters such as effective carrier mobility and transit time for both complexes. Complex 1 is found to be more conductive. To obtain insight into the physical nature of weak non-covalent interactions, Bader's quantum theory of atoms-in-molecules (QTAIM) is used extensively. Additionally, the non-covalent interaction reduced density gradient (NCI-RDG) methods established nicely the presence of such non-covalent intermolecular interactions.