A first-principles computational and experimental investigation on schiff base cobalt complex towards designing solar cells

Abstract

A synthesized cobalt complex (Co-NG) based on a Schiff base, derived from ninhydrin and glycine ligand, with cobalt Co (II) metal is presented. A combined theoretical and experimental study is performed. The Co-NG crystalline structure is obtained from XRD spectra, which reveals that the crystal belongs to the triclinic system. Furthermore, the FT-IR spectrum clearly shows that the complex behaves as tridentates monobasic ONO donor ligand. In addition, the optical observations in different solvents show a good absorption in visible especially in Dimethyl sulfoxide (DMSO) solvent with two maxima around 415 nm and 604 nm. Moreover, the Density Functional Theory (DFT) calculations reveal that the Co-NG complex has an energy gap equal to 2.85 eV, where the LUMO energy of the dye is above the TiO2 conduction band and the HOMO energy is below the electrochemical potential of redox couple I−/I3− in the electrolyte. Finally, some photovoltaic parameters including the electron injection () and the redox process rate (), which are equal to – 0.29 eV and - 1.82 eV, respectively, are estimated. These interesting properties make the Co-NG complex a potential sensitizer for dye sensitized solar cell devices