New organic dyes based on phenylenevinylene for solar cells: DFT and TD-DFT investigation

Combined Theoretical and Experimental Study on Intramolecular Charge Transfer Processes in Star-Shaped Conjugated Molecules

“…Different TD-DFT methods (TD-B3LYP, TD-PBE0, and TD-M06–2X) and basis sets (6-31G* and 6-31+G*) were employed to calculate the lowest-energy electronic transitions of both molecules in the chosen solvents (see Table S3 in Supporting Information). High oscillator strengths were found for these transitions ( f ≥ 1.2; see Table ) in agreement to the previous observations reported for compound 3b , other related phenylenevinylenes, and, in general, systems with large number of conjugated rings such as coumarins, porphyrins, phthalocyanines, and graphene nanoribbons, among others. ,− The combination of TD-M06–2X and 6-31+G* yielded the best match between calculated and experimental values. The higher percentage of HF-like exchange in M06-2X, compared to B3LYP and PBE0, reduces any possible underestimation in the calculation of the excited-state energies, in agreement with previous works. ,, According to the findings obtained with TD-M06-2X/6-31+G*, the lowest energy absorption band of compound 1 corresponds to two π–π* electronic transitions whose main components are HOMO–1 → LUMO and HOMO → LUMO electronic excitations (see Table ).…”

“…High oscillator strengths were found for these transitions (f ≥ 1.2; see Table 2) in agreement to the previous observations reported for compound 3b, other related phenylenevinylenes and, in general, systems with large number of conjugated rings such as coumarins, porphyrins, phthalocyanines and graphene nanoribbons, among others. 17,[52][53][54][55][56][57] The combination of TD-M06-2X and 6-31+G* yielded the best match between calculated and experimental values. The higher percentage of HF-like exchange in M06-2X, compared to B3LYP and PBE0, reduces any possible underestimation in the calculation of the excited-state energies, in agreement with previous works.…”

DFT Study of Leuco-Indigo and Indigo as Active Material in Dye-Sensitized Solar Cell

“…There are many researchers who used DFT B3LYP/6-31G(d,p) as the model theory for calculation natural dyes as a photosensitizer in DSSC. El Alamy et al (2017) have been used DFT and TDDFT with the B3LYP/6-31G(d,p) to calculate new compounds based on phenylenevinylene and thiophene/furan which determined and investigated geometries and optoelectronic properties (El alamy, Bourass, Amine, Hamidi, & Bouachrine, 2017). Irfan et al (2018) have been investigated stable structure, electro-optical, charge transport and nonlinear optical properties of (4Z)-4-Benzylidene-2-(4-methylphenyl)-1,3-oxazol-5(4H)-one and its derivatives using DFT and TDDFT with the B3LYP/6-31G** (Irfan, Al-Sehemi, Chaudhry, & Muhammad, 2018).…”

Density Functional Theory Investigation of Fulvene-Derivatized Fullerenes as Candidates for Organic Solar Cells

“…Over the past few years, computational molecular modeling, particularly density functional theory (DFT), has served as a valuable tool for evaluating the suitability of electron-acceptor candidates based on criteria such as HOMO and LUMO energy, HOMO–LUMO band gap, and dipole moment. − The B3LYP − density functional is most commonly utilized for these analyses despite its shortcomings in band gap calculations. , Recently, McKechnie found that the closest agreement of theoretical versus experimental vertical ionization energy (VIE) values (equivalent to the negative of the HOMO energy) of over a hundred small molecules was achieved in DFT methods with either large amounts of exact exchange or long-range correction . Specifically, the energy of the HOMO is severely underestimated by hybrid functionals that include smaller amounts of exact exchange like B3LYP.…”