Quantum Chemical Elucidation on the Optoelectronic Properties of N2-(4-Aminophenyl)Pyridine-2,5-Diamine Based Dyes for Solar Cells Utilization

Demand for CO2 free renewable energy source never cease. Renewable energy is germane for energy crisis solution. Solar cell as a renewable energy is relevant to solve energy issues and global warming. However, modulation of metal free organic dyes is efficient to achieve a dependable dye-sensitizer for solar cells purposes. In this study, three sets of new organic D − π − A sensitizers consisting of three dyes in each set were reported. The optoelectronic and chemical properties were examined via density functional theory (DFT) and time dependent density functional theory (TD-DFT) techniques. It was observed that 6H-borolo[3,4-b]pyrazine containing molecules (CX3, TX3 and PX3) have a shorter bond length (∆r) and small dihedral angle (ɸ1) which impart lower energy gap (∆Eg) and longer absorption wavelength (λmax). The calculated result of the chemical reactivity parameters further revealed that 6H-borolo[3,4-b]pyrazine containing dyes have lower resistance to charge transfer and greater ability for photon absorption than other dyes. The results of open circuit voltage (Voc), light harvesting efficiency (LHE) and electron injection driving force (ΔGinject) calculated for the dyes showed that all the simulated dyes have good photoelectric conversion efficiency properties but with low dye regeneration (ΔGregen) ability. Notably, high excited state lifetime (τesl) values of 6H-borolo[3,4-b]pyrazine containing dyes would lead to stability of the dyes in the cationic state for a longer time which may result in higher charge transfer efficiency; thus, enhancing electron injection efficiency of the dye-sensitizers for DSSC.