Acceptor tuned effect on the D-π-A-based organic efficient sensitizers for optoelectronic properties using quantum chemical study

The analysis to plan for high-efficiency with affordable molecules such as coumarin, prop-1-ene with 2-cyano-N-hydroxyacrylamide (A1), 2-cyanoprop-2-enedithioic acid (A2), 1-cyanovinylphosphonic acid (A3) and 1-cyanoethenesulfinic acid (A4) are one of the most important aspects of improving the non-linear optical (NLO) property besides dye-sensitized solar cells (DSSCs) applications. NKX-2311 has been taken as a literature molecule, it contains coumarin as a donor moiety (D), prop-1-ene as a π-spacer (π) and cyanoacrylic acid as an acceptor moiety (A). The three fragments that make up the D-π-A structure. The family of A1-A4 metal-free organic coumarin NKX-2311 dye derivatives have examined for applications involving optoelectronics in this research. Density functional theory (DFT) and time-dependent DFT (TD-DFT) techniques utilizing quantum chemical calculations, the molecular electronic structures, ultra-violet visible (UV–Vis) absorption, transition density matrix (TDM), electron–hole mobilities (reorganization energies) and photovoltaic (PV) characteristics of the A1-A4 sensitizers have been calculated. For optoelectronic devices, the effect of chemical alteration on the UV–Vis spectra about PV parameters of the NKX-2311 were illustrated. The performance of hybrid functionals such as B3LYP, CAM-B3LYP and ωB97XD was assessed to compare with the absorption wavelength of NKX-2311. The B3LYP method and NKX-2311 have had a superior fit based on the selected functionals. Consequently, the B3LYP/6-31G(d) theory has been used to study the excited state computations of A1-A4 dyes at UV–Vis wavelengths. The findings demonstrate that A2 dye has a smaller energy gap and that UV–Vis spectra were constantly redshifted. According to the computational outcomes, the A1-A4 sensitizers can respond positively to the processes of dye regeneration and electron injection based on their lowest unoccupied and highest occupied molecular orbitals (LUMOs and HOMOs), respectively. A2 dye has the greatest hole mobility due to its lowest λ_ + value of 0.1701 eV, while A1 dye has extreme electron mobility due to its lowest λ_ - value of 0.2273 eV. The NLO property of molecules A1-A4 has been calculated by two ways such as polarizability and first-order hyperpolarizability. The most promising candidate for NLO performance has been identified as the dye with computed values of A2. The results would serve as a useful resource for any upcoming demands and also more advantageous for obtaining optoelectronic applications.