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A new generation of metal-free organic dyes with a range of donor (D1) and acceptors (A1-A3) were designed and examined for dye-sensitized solar cells (DSSCs) based on (3a) dye as a literature. Triphenylamine (TPA), thiophene (π) and 2-cyanoacrylic acid groups each perform the roles of an acceptor (A), donor (D) and spacer in order to produce a D- π -A system. To investigate the intramolecular charge transfer (ICT), electronic distribution, ultra-violet visible (UV–Vis) absorption wavelengths, molecular electrostatic potential (MEP) and photovoltaic (PV) parameters of the D1 and A1–A3 molecules, density functional theory (DFT) and time-dependent DFT (TD-DFT) were used. The classification of the tunable donor D1 and A1–A3 determines the PV performance of the dye molecules. Results show that the A2 dye replacement group increases the performance of PV cells via red-shifting absorption spectra. Also, when compared to 3a, A2 dye have lower energy gap ( E g) and superior UV–Vis spectra that cover the full visible range. These results demonstrate the viability of molecular tailoring as an approach to improve D- π -A sensitizer proposal for efficient DSSCs fabrication. Perylene-based organic dyes (D1 and A1–A3) are designed and systematically investigated for DSSCs. To investigate the intramolecular charge transfer (ICT), electronic distribution, ultra-violet visible (UV–Vis) absorption wavelengths and photovoltaic (PV) parameters of the D1 and A1–A3 molecules, density functional theory (DFT) and time-dependent DFT (TD-DFT) were used. All the dyes might be used for the potential in DSSCs. [ABSTRACT FROM AUTHOR]

Four metal-free carbazole-based acceptor-tuned organic molecules (denoted as CBa1–CBa4) based on electron-donor, π -spacer and electron-acceptor (D- π -A) for dye-sensitized solar cells (DSSCs) have been newly designed. The electronic structures, optical absorption ultraviolet-visible (UV–Vis) properties and photovoltaic (PV) parameters of CBa1–CBa4 dyes were computationally studied by the density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. These molecules were planned through chemical alterations of the acceptor group of a literature-based organic dye known as CB1 dye. The planning of CBa1–CBa4 dyes was to decrease the highest occupied molecular orbitals (HOMOs) and lowest unoccupied MOs (LUMOs) of the energy gap ( E g ) and to red-shift their UV–Vis response compared to CB1. This study was initially performed using the exchange correctional (XC) and long-range corrected (LC) with the computational ideal in the TD-DFT method significantly to get an accurate absorption wavelength for CB1. From the XC and LC results, CAM-B3LYP functional is better matched with CB1. So, further newly organic CBa1–CBa4 dyes UV–Vis spectra were followed by this method. According to DFT and TDDFT results, CBa1 and CBa2 molecules were found to have reduced HOMOs–LUMOs energy gap, longer UV–Vis spectra and faster charger transfer (CT) character compared to CB1. The conclusion recommends that the newly designed molecules are hopeful and appropriate for optoelectronic devices. Hence, the work predicts to support the new scheming carbazole-based molecules with the studied properties for synthetizing to DSSC applications. Carbazole-based organic dyes are designed and theoretically investigated. A CAM-B3LYP functional is well matched with CB1. Simulated UV-Vis absorption of the CBa1 and CBa2 dyes displayed best act for solar cell applications. All the dyes might be used for the potential in DSSCs. [ABSTRACT FROM AUTHOR]

Cobalt Oxide (Co3O4) nanoparticles were synthesized with an aid of urea by sol–gel method. The results of X-ray diffraction revealed that the formation of face-centered cubic (Fd3m) structure and the average crystallite size of the product were found to be 13.76 nm. The formation of cobalt oxide is confirmed by FT-IR analysis. The results of HR-TEM images reveal that Co3O4 nanoparticles were found to have within the range of 13–15 nm. At 3 M KOH, electrochemical analyses were investigated with impedance spectroscopy and an intrinsic pseudo capacitance and the results were reported. The results of Galvanostatic charge-discharge (GCD) tests revealed the capacitive properties of Co3O4 with the highest specific capacitance of 761.25 F g−1. Highlights: The specific capacitance of Co3O4 nanoparticles was found to be 761.25 F g−1 at 11 mA/cm2 current density. The Co3O4 nanoparticles were synthesized by a simple sol–gel method. The crystallite size of Co3O4 nanoparticles was found to be 13.76 nm. [ABSTRACT FROM AUTHOR]