The process of effective solar energy harvesting and conversion requires efficient photon absorption, followed by charge generation and separation, then electron transfer. Nanostructured materials have been considered as potential building blocks for the development of future generations of solar cells. Much attention has been given to wide-bandgap semiconductor nanowires, combined and sensitized with low-bandgap semiconductors effectively attached to the nanowires for low-cost and highly efficient solar cells. Here, the in situ growth of lead sulfide (PbS) nanoparticles on the surface of zinc oxide (ZnO) nanowires grown by the Successive Ionic Layer Adsorption and Reaction (SILAR) technique is presented for different numbers of cycles. The morphology and structure of PbS nanoparticles are confirmed by Scanning Electron Microscopy (SEM), revealing the decoration of the nanowires with the PbS nanoparticles, Transmission Electron Microscopy (TEM) and HR-TEM, showing the tight attachment of PbS nanoparticles on the surface of the ZnO nanowires. The Selected Area Electron Diffraction (SAED) confirms the crystallization of the PbS. Photoluminescence spectra show a broad and more intense deep-level emission band.

The nanowires (NWs) of zinc oxide (ZnO) are developed effectively on an n-type silicon substrate through a seed zinc (Zn) layer by a wet oxidation technique. The growth is performed at different temperatures, 650, 750, and 850 °C, in a wet and rich oxygen environment under a flow of oxygen in the presence of water vapor at atmospheric pressure with a heating rate of 100 °C in 30 min. At 415 °C, the oxygen gas is introduced for the oxidation process. The Zn seed layer is deposited by the thermal evaporation technique. The structural, morphological, and optical properties are investigated. The temperature effect on NWs of ZnO growth intensity and their direction are explored. The nanowires are grown vertically oriented at a temperature of T = 750 °C. The ultraviolet (UV) analysis has been exposed in the visible region ranging from 10 nm to 700 nm at UV to visible intensity ratio of 2.22. In addition, X-ray diffraction analysis (XRD) is employed to research the structural properties of NWs of ZnO, and the characterization is verified by a scanning electron microscope (SEM) to investigate the morphology.

Iron(II) complexes bearing N-heterocyclic carbene (NHC) ligands have emerged as promising earth-abundant dye sensitizers for applications in dye-sensitized solar cells (DSSCs). In this work, we present a computational study of a set of 42 Fe–NHC dyes derived from seven ligand frameworks, systematically functionalized with donor, acceptor, and donor–acceptor groups to tune or enhance their photophysical properties. The calculated geometries reveal that substitution modulates Fe–N bond lengths and ligand dihedral angles only slightly, preserving the structural integrity of the complexes. TD-DFT calculations show clear and predictable electronic trends: donor groups raise the HOMO, acceptor groups lower the LUMO, and the combined push–pull configuration produces the most pronounced HOMO–LUMO gap narrowing and largest redshifts in MLCT transitions. Key DSSC performance descriptors, including electron-injection and dye-regeneration free energies, light-harvesting efficiency, excited-state lifetimes, and hole-transport reorganization energies, collectively identify the double-acceptor and push–pull derivatives as the most promising candidates across multiple frameworks.

Femtosecond laser direct writing on Kapton polyimide was investigated using ultraviolet (343 nm) and near-infrared (1030 nm) irradiation. Sixteen conditions were screened optically and electrically. Scanning electron microscopy (SEM) micrographs were obtained for four infrared conditions and one ultraviolet condition; van der Pauw measurements were performed on the ultraviolet- and infrared-processed samples, and X-ray diffraction (XRD) was performed on the infrared sample with the lowest reported sheet resistance (IR-O1). None of the twelve ultraviolet conditions produced a measurable electrical response, whereas all four infrared conditions yielded measurable sheet resistances. The lowest reported sheet resistance, 65.1 Ω/□, was obtained at a repetition rate of 200 kHz, a nominal power setting of 5%, and a scan speed of 20 mm s⁻¹. XRD analysis of IR-O1 revealed an additional broad reflection in the graphite (002) region, supporting graphitic stacking in that sample. Bond scission and aromatization of polyimide, as described in the literature, provide a possible molecular pathway to graphitic stacking, although this pathway was not directly investigated. Quantitative SEM analysis did not resolve differences in the apparent open-porosity area fraction across the infrared conditions, despite variations in sheet resistance; the present data do not establish the mechanism responsible for these variations. Because the ultraviolet and infrared conditions differed in repetition rate and nominal power setting, wavelength cannot be isolated as the cause of their different electrical outcomes. These findings highlight the importance of combining electrical and microstructural characterization when assessing femtosecond-laser-modified Kapton.