An electrically conductive dinuclear aluminium complex for the fabrication of a Schottky diode

Abstract

Electrical performances of a biphenyl-derived amido Schiff base ligand L and its dinuclear Al(III) complex (complex 1) were investigated in a metal–semiconductor (MS) junction. Electrical studies revealed that complex 1 significantly enhanced the electrical conductivity and improved the characteristics of a Schottky barrier diode (SBD). The I–V characteristics demonstrated that complexation of ligand L with Al(III) ion increased the conductivity by two orders of magnitude (conductivity of L = 1.04 × 10⁻⁷ Sm⁻¹ and complex 1 = 1.04 × 10⁻⁵ Sm⁻¹) with improved diode rectification ratio. Complex 1 extended itself to the 3D supramolecular array by virtue of the hydrogen bond, C–H⋯π(C) bond and π⋯π interactions. This significantly influenced the semiconducting behaviour of complex 1 and essentially improved the characteristics of SBD. The optical band gap of complex 1 and ligand L in the solid state was determined experimentally (2.63 eV and 3.04 eV, respectively) and compared with the theoretical value obtained from DFT calculations. Furthermore, DOS analysis explained the conductivity behavior of complex 1 in a logically better way.