In this report, a physicochemical study was performed on a series of organic dyes (AE, AQ, TE, and TQ) in the gas phase and solvent through the molecular approach. Triphenylamine/dimethylaniline as electron donors and 1,1,4,4-tetracyanobuta-1,3-dienes (derived from TCNE)/ 2-(4-(4,4-dicyanobut-3- en-2-ylidene)cyclohexa-2,5-dien-1-ylidene)malononitrile (derived from TCNQ) as the electron accep- tors were utilised in this system. The introduction of strong electron acceptors of TCNE and TCNQ elevates electron transfer processes and makes the suggested dyes favourable to be used in the dye-sensitized solar cell (DSSC). On the basis of the obtained results, TCNQ-adduct dyes (AQ and TQ) have the highest charge transfer distance, excited-state lifetime, and the lowest overlap of the elec- tron–hole distribution in comparison with TCNE-adduct dyes (AE and TE). The analysis of the charge transfer indices shows the amplification effect of the solvents in comparison with the gas phase and DMF as the solvent represents the best performance. Also, the maximum electron transfer rate con- stant and minimum electronic chemical hardness belong to the TCNQ-adduct dyes. Finally, AQ and TQ as the dyes and DMF as the solvent are introduced as the most promising candidates to be applied in the DSSCs due to efficient charge transfer and electron transfer rate constant

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