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Pyrene‐based molecules are being explored as prospective fullerene‐free acceptors for organic solar cells (OSCs), due to their easy accessibility, structural planarity, and excellent electron delocalization. In this work, we successfully designed and analyzed pyrene‐based acceptor materials (QL1–QL8) to investigate their photophysical and electro‐optical parameters. Various geometric parameters were computed at the MPW1PW91/6‐31G(d,p). Advanced quantum chemical approaches were employed to characterize the molecules. All the tailored molecules (QL1–QL8) exhibit a lower bandgap than the reference (R), signifying their superiority. Among these, QL8 was found to have a maximum absorption (λmax) at 791.37 nm and an optical bandgap (ELUMO − EHOMO) minimum of 2.11 eV. Redshifted absorption spectra are observed in both gaseous and solvent phases for all the designed (QL1–QL8) molecules in contrast to R. Among these, QL4 exhibits the highest light harvesting efficiency (0.9826), and open‐circuit voltage. A detailed donor–acceptor investigation of QL8/PBDB‐T revealed the marvelous charge switching at the donor–acceptor interface. The approach used in this study is anticipated to facilitate the manufacturing of highly efficient OSC molecules. [ABSTRACT FROM AUTHOR]

In this study, density functional theory has been used to investigate the geometric, electronic, linear and nonlinear optical properties of exohedrally and endohedrally doped adamanzane M1(26 adz)M2 where (M1 = M2 = Be, Mg and Ca). The multiple doping rendered excess electrons to the system which resulted in increased HOMO energies and resultantly reduced HOMO‐LUMO gap (from 8.85 eV to 4.87 eV). The significant changes in excitation energy and vertical ionization energy indicated the introduction of excess electrons to the system. The NBO analysis confirmed that both the dopants are electron donating moieties. The formation of new HOMOs were also evident from the density of state (DOS) analysis. The new complexes exhibited remarkable nonlinear optical response and maximum first hyperpolarizability (β = 8.19 × 103 au) and second hyperpolarizability (γ = 8.12 × 105 au) were observed for AM9. This nonlinear response enhanced significantly when materials were placed in the light of 1907 nm wavelength for determination of dynamic hyperpolarizabilities. The UV–Vis analysis confirmed the transparency of designed materials in deep UV region. The structural properties of new materials were also authenticated by IR‐spectra. The exceptionally high nonlinear response makes these materials desirable candidates for photonic, telecommunication and laser applications. [ABSTRACT FROM AUTHOR]

Theoretical study of super salt doped on B12N12 was conducted using density functional theory. B3LYP is used with basis set LanL2DZ (a suitable basis set for metal atoms). The structural properties were characterized by molecular geometry analysis, global stability factors, non-covalent interaction, molecular electrostatic potential and infra-red vibrational spectra analysis. The electronic properties were observed by FMOs analysis, the density of states analysis, non-bonding orbitals analysis, excitation energy and transition density matrix analysis. The nonlinear optical properties were observed by calculating polarizability and hyperpolarizability. The values were outstandingly incremental in all the above results compared to B12N12. The hardness values of all complexes are lower (0.41–1.19 eV) as compared to B12N12 (3.42 eV). The excitation energy of all the complexes was observed lower (0.84–2.92 eV) than higher value of B12N12 (5.84 eV). The hyperpolarizability values significant increases in the doped complexes that was observed (up to 922.80 a.u and 334,849.62 a.u in BNSS4a, respectively) as compared to B12N12 (158.19 a.u and 0.000751 a.u, respectively). [ABSTRACT FROM AUTHOR]

In this work, pure and supersalt-doped graphene is evaluated by the density functional theory (DFT) to explore its optical and electronic properties. The doping of supersalt Al(BH4)3 on graphene reduces the highest occupied molecular orbital and lower unoccupied molecular orbital (HOMO–LUMO) bandgap of graphene@Al(BH4)3 and graphene@2Al(BH4)3 to 3.57 and 3.55 eV from 3.61 eV. The improvement in the optoelectronic properties of the supersalt Al(BH4)3-doped graphene is determined by the upshift of UV absorption peak and dipole moment. Polarizability (α) values of graphene@Al(BH4)3, and graphene@2Al(BH4)3 increase to 14% and 26% in the comparison of pure graphene. The first hyperpolarizability (βo) is increased from 0.44 (graphene) to 1295.4 au in graphene@2Al(BH4)3. Our findings suggest that Al(BH4)3-doped graphene could be an effective method for making graphene an efficient nonlinear optical material. [ABSTRACT FROM AUTHOR]

Recently, scientists are more devoted to designing and synthesizing organic perovskite solar cells for attaining high power conversion efficiency (PCE). Herein, a series of small molecules as hole transport materials with A–π–D–π–A framework, namely (DFA1, DFA2, DFA3, and DFA4) having triphenylamine (TPA)‐based central donor core unit (A1–A4) end‐capped acceptor moieties linked via thiophene spacer is designed theoretically to study optoelectronic and photovoltaic properties. MPW1PW91 hybrid functional in conjunction with 6‐31G** basis set is found the best method to investigate the optoelectronic and photovoltaic properties. All hole transport materials (HTMs) possess a high open‐circuit voltage (0.98–1.41 V) with downshifted highest occupied molecular orbital energy values (−4.98 to −5.41 eV) by tailoring of electron‐withdrawing acceptor moieties. Meanwhile, appropriate elongation of π‐conjugated acceptor units is advantageous for enhancing the molar absorption coefficient and intermolecular electronic coupling. The highest hole mobility and charge transfer integral owing to lower hole reorganization energies indicate these molecules are best for HTMs. DFA1‐DFA4 has a power conversion efficiency of up to 24% which authenticates that these HTMs have excellent photovoltaic attributes compared to the reported reference DFH. The present computational investigation validates the efficacy of the designed techniques and opens a new route for designing high‐performance dopant‐free HTMs in perovskite solar cells. [ABSTRACT FROM AUTHOR]

A series of D‐π‐A type molecules have been designed for their potential use in organic photovoltaic devices. Photovoltaic and optoelectronic properties of newly designed molecules have been explored by comparing with a reference molecule R comprising of the central core (2,3,8,9‐tetrakis(thiophen‐2‐ylethynyl)‐5,7,10,12‐tetrakis((trimethylsilyl)ethynyl)pyrazino[2,3‐b]phenazine) and π‐bridge (thiophene). The end groups are (2‐(2‐ethylidene‐3‐oxo‐2,3‐dihydro‐1H‐inden‐1 ylidene)malononitrile), (2‐ethylidenemalonitrile), (methyl 2‐cyanoacrylate) and (3‐methyl‐5‐methylene‐2‐thioxothiazolidin‐4‐one) in the newly designed molecules. Among the investigated molecules M1 and M2 exhibit a broad absorption range of 627 and 626 nm with respect to the reference. All the designed molecules exhibited a lower bandgap as compared to R which indicates a better transfer of electron density from highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO). The reorganization energy values show that all designed molecules have efficient charge transport capability. This study proves that end‐capped acceptor modification is an effective strategy for designing optimistic molecule for high performance future organic solar cells fabrication. [ABSTRACT FROM AUTHOR]