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The present work is involved in the computational and experimental studies of organic dyes and their applications as dye-sensitized solar cells (DSSCs). This comprised the study of three hydrazone-based sensitizers (E)-2-cyano-N′-((2-hydroxynaphthalen-1-yl)methylene)acetohydrazide (CHMA), (E)-2-cyano-N′-(4-(dimethylamino)benzylidene)acetohydrazide (CDBA), (E)-N′-(anthracen-9-ylmethylene)-2-cyanoacetohydrazide (AMCH) that have been prepared and confirmed by means of several analytical procedures like Fourier transform infrared, UV–visible and nuclear magnetic resonance techniques to investigate the best possible selection for DSSCs by computational and experimental techniques. The computational methods are applied to optimize the structures of prepared organic dyes via density functional theory (DFT) method at B3LYP/6-311G(p,d) level of theory. The time-dependent DFT (TD-B3LYP/6-311G**) was used with and without solvent to find out the absorption spectra and matched with the experimental data and the electro-optical and reorganization energies of prepared dyes were further investigated. The results revealed that the prepared dyes would be better sensitizers for DSSCs because of small highest-occupied molecular orbital–lowest-unoccupied molecular orbital energy gap. Moreover, on the basis of the above results, we fabricated the devices via the doctor blade method to study the photovoltaic performance with the prepared dyes (CHMA, CDBA and AMCH). The dye AMCH exhibited the maximum efficiency with commercial TiO2. [ABSTRACT FROM AUTHOR]

The synthesis and study of doped semiconducting nanomaterials have drawn great importance to researchers over the last few years. In the present study, we premeditated the structural, morphological and optical properties of gadolinium-doped zinc oxide (GZO) nanomaterials. The GZO powders were synthesized by modified solvothermal method by doping with Gd at 80 °C and characterized by XRD, FTIR, UV–Vis, SEM–EDX, TEM, SAED and HRTEM. The GZO with 5% doping of Gd exhibited maximum diffraction peak intensity. The XRD results exhibited that the crystallite size of Gd-doped ZnO nanomaterials was varied with Gd doping. The size of crystals first decreased then increased (50, 39 and 44 nm) with increasing the percentage of Gd from 5 to 15%, demonstrating the propensity of considerable grain growth in the nanomaterials due to doping of a high percentage of Gd. The morphology displayed by SEM and TEM micrographs is almost the same as irregular spherical shapes and small tiny particles on the surface of ZnO, which twisted into larger spherical ones with increasing Gd percentage. The optical band gap ranges from 2.87 to 2.93 eV with increasing the doping concentration of Gd, which reflects that the optical properties are affected by the doping of Gd. [ABSTRACT FROM AUTHOR]