The impact of carboxylic acid anchoring groups on the optoelectronic and nonlinear optical properties of Ru complex dyes: A computational approach

Abstract

In this study, density functional theory (DFT) and time-dependent DFT (TD-DFT) methods were used to analyze the effects of varying the number and positions of carboxylic acid anchoring groups attached to the bpy ligand of the [Ru(bpy)2(NCS)2] complex. Also the geometric structures, absorption geometry, electronic structures, optical properties, photovoltaic parameters, and nonlinear optical (NLO) properties of the designed [Ru(bpy)2(NCS)2] derivatives were investigated and compared with each other. The results indicate that the optoelectronic properties of these ruthenium (II) complexes are influenced by the number and positioning of carboxylic acid groups on the bipyridine moiety. Calculated values of ΔGinject and ΔGreg for the studied Ru(II) complexes suggest that the energy level alignment with the semiconductor and electrolyte satisfies the criteria. Furthermore, it was observed that the number and position of the anchoring carboxylic acid units is an effective approach to improve their NLO response. Overall, the structural modifications by the anchoring carboxylic acid groups on the bpy ligand of [Ru(bpy)2(NCS)2] complexes seem to fine-tune their DSSC performance and NLO response characteristics.

Keywords

• TD-DFT
• Ruthenium complex
• DSSCs
• NLO
• Photovoltaic property