Browsing by Author "Ahia, Chinedu Christian"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Advances in the Use of Atomic Force Microscopy as a Diagnostic Tool for Solar Cells Characterization: From Material Design to Device Applications
    (Wiley, 2023-12-03) Ahia, Chinedu Christian; Meyer, Edson L.
    Considerable efforts in search for an effective characterization technique for photovoltaic devices with utmost precision is on the increase. For precise analysis and tailoring of device performance, a reliable technique is vital. Atomic force microscopy is one of the leading surface analysis techniques of choice for probing surface patterns in a variety of materials with atomic precision using a cantilever. It has evolved as a reliable technique for the investigation of subatomic scale properties of materials such as photocurrent heterogeneity, electromechanical response, charge distribution, molecular weight effects, and many other material parameters. The integration of artificial intelligence hybrid algorithms in atomic force microscope for optoelectronic device fabrication and characterization has increasingly emerged to be desirable due to its reliability and effectiveness in achieving high image resolution, automated analysis, actuation, and the coupling of manufactured units with a precision down to atomic units. In this review, an investigation of topical developments in the use of atomic force microscopy as a diagnostic tool for solar cells characterization is presented with special focus on polymer solar cells, perovskite solar cells, quantum dots-sensitized solar cells, dye-sensitized solar cells, fullerene-based solar cells, III-V-based solar cells, and silicon-based solar cells.
  • No Thumbnail Available
    Item
    Development of cupric sulphate nanocrystals on fluorine-doped tin oxide substrates using hydrothermal technique
    (Springer, 2023-06-29) Ahia, Chinedu Christian; Meyer, Edson L.
    Cupric sulphate nanocrystals (NCs) are desirable for a number of applications. The NCs were grown using a hydrothermal technique on Fluorine-doped Tin Oxide substrate which was sandwiched into the grooves of a sample holder at an angle between 45 and 90 relative to the wall of a 100 ml Teflon container. The surface features were observed using an optical microscope while atomic scale features which are not visible under the optical microscope were investigated using a scanning electron microscope and atomic force microscope. Details of the weight percentage composition were investigated on the sample by means of energy-dispersive X-ray spectroscopy. A broad absorption spectrum from 690 to 1100 nm, having a full width at half maximum value of 254 nm and an energy excitonic absorption peak in the visible region at 810 nm, was observed when the NCs are dissolved in water (hydrate solution) contrary to the highest absorption peak which was observed at 678 nm for the anhydrous compound. A total number of 16 vibrational frequencies were observed from Raman scattering while five active modes were visible in the Fourier Transform Infrared spectrum. Information on room-temperature photoluminescence and fluorescence spectroscopy measurements obtained from the NCs is reported. The deposition technique adopted in present work could be optimized for the high-yield production of more uniform layers of ultrathin nanostructures with increased aptitude for various applications.