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The increasing demand for energy expedited the development of efficient photovoltaic materials. Herein, four triphenylamine based push pull donor materials (D1-D4) have been designed. The optical, electronic, photophysical properties and excited state energy of D1-D4 have been investigated theoretically through DFT calculations at B3LYP/6-31G (d,p) level of theory and compared with reference molecule R. The theoretical study of the designed molecules (D1-D4) and reference molecule R with TDÀ B3LYP/6-31G (d,p) level of theory was carried out both in gaseous and solvent (Chloroform/CPCM) phase to investigate their excited state properties. All the designed molecules D1-D4 exhibited broad and intense absorption peaks in the visible spectrum from 300 nm to 450 nm range with narrow HOMO-LUMO energy gaps as compared to reference R. The dipole moment of designed molecules D1-D4 are higher than reference molecule R in both gas and solvent phase which may help to enhance the photovoltaic stability of organic solar cells devices. The open-circuit voltages V oc of designed molecules, D1-D4 and the reference molecule R compared to PCBM are 0.71 V, 0.66 V, 0.54 V, 0.63 V, and 0.63 V, respectively. The % ETC for designed molecules insolvent as well as in the gas phase is lower than the reference molecule R which enables them to excite rapidly both in gas and solvent phase respectively. The hole and electron transfer mobilities values indicate that the designed molecules have a better electron and hole transport mobility values as compared to reference molecule R. Furthermore, conceptualized molecules are better and thus are recommended to experimentalists for out-looking future developments of solar cells.

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Sequential all-dip-coating processed perovskite materials was conducted in an aqueous non-halide lead precursor solution, which was followed by that in a mixed halide solution for high-efficiency perovskite solar cells.

Herein, we have designed four small molecular donors (SMDs) with Donor–Acceptor–Acceptor (D–Á–A) backbone having different acceptor units for highly efficient organic solar cells (OSCs). The specific molecular modeling has been made by replacing the additional acceptor unit (A) of recently synthesized TPA-DAA-MDN molecule (R) by employing different highly efficient acceptor units in order to improve the photovoltaic performances of the molecules. A theoretical approach (DFT and TD-DFT) has been applied to investigate the photophysical, opto-electronic and photovoltaic parameters of the designed molecules (DAA1–DAA4) and compared with the reference molecule (R). The red-shifting absorption of SMDs is the most important factor for highly efficient OSCs. Our all formulated molecules showed a red shifted absorption spectrum and also exhibit near IR sensitivity. Acceptor unit modification of R molecule causes reduction in HOMO-LUMO energy gap; therefore, all designed molecules offer better opto-electronic properties as compared to R molecule. A variety of certain critical factors essential for efficient SMDs like frontier molecular orbitals (FMOs), absorption maxima, dipole moment, exciton binding energy along with transition density matrix, excitation energy, open circuit voltages and charge mobilities of (DAA1–DAA4) and R have also been investigated. Generally, low values of reorganizational energy (hole and electron) offer high charge mobility and our all designed molecules are enriched in this aspect. High open circuit voltage values, low excitation energies, large dipole moment values indicate that our designed SMDs are suitable candidates for high-efficiency OSCs. Furthermore, conceptualized molecules are superior and thus are suggested to experimentalist for out-looking future progresses of highly efficient OSCs devices.

Efficient molecular modeling approaches draw great attention from the scientific community to further boost the photovoltaic performances of the solar cell's materials. For this purpose, various end-capped and bridged-core modifications have been carried out to construct a suitable molecule best fitted for solar cell applications. Herein, we have designed a small-molecule-based fullerene-free acceptor materials (IOD1-IOD7) for organic solar cells (OSCs)

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