Review: Low Temperature Sintering of TiO2 for Dye Sensitized Solar Cells (DSSCs) Fabrication on Flexible Substrates (Published)
This article discusses the most recent developments in the manufacture of flexible dye-sensitized solar cells (DSSCs), with a focus on the use of flexible plastic substrates instead of rigid glass substrates. The temperature restriction of the substrate in generating TiO2 nanoparticles is a key problem for creating DSSCs on plastic substrates. Ball-milling, acid/water treatments, chemical vapor deposition, and electrophoretic deposition, as well as chemical and mechanical film processing methods such as chemical sintering, hydrothermal treatment, microwave irradiation, and various compression techniques, are all discussed here. It also includes research on novel flexible counter electrode manufacturing processes and recently produced new materials that are particularly beneficial for flexible DSSCs. Finally, the progress and possibilities of large-scale flexible DSSC module fabrication, as well as their endurance, are reviewed.
Citation: Wante, H. P., Bala S. & Romanus I.O. (2022) Review: Low Temperature Sintering of TiO2 for Dye Sensitized Solar Cells (DSSCs) Fabrication on Flexible Substrates, European Journal of Material Science , Vol.9, No.1, pp.18-24
Keywords: Fabrication, Review, TiO2, dye Sensitized solar cells (DSSCs), flexible substrates, low temperature sintering
Dependence of Optical Band Gap on Crystallite Size of TiO2 Thin Films Prepared Using Sol Gel Process (Published)
We report on a simple and robust analysis of the energy band gap and crystal size of anatase TiO2 thin films on doped Fluorine Tin Oxide (SnO2:F) prepared using sol-gel Doctor-blade method. The films had been annealed at rates of 1oC/Min, 2oC/Min, 1-step and referenced with as-deposited film, and the optical and structural properties characterized using UV-VIS spectrophotometer and X-ray diffraction (XRD), respectively. The films had a refractive index which was noted to depend on the annealing rate consistent with Cauchy’s relation. An optical band gap of , , , and was measured on the as-deposited, 1-Step, 2oC/Min and 1oC/Min annealing, respectively. Optical conductivity was highest in the UV region and diminished sharply in the visible region in all the annealed samples. The as-deposited film exhibited a diminished optical conductivity in the visible electromagnetic field due to high density of charge trapping sites resulting to negligible interaction of the film molecules with the applied electric field. The XRD spectra revealed thermal enhancement in crystallinity, with the crystallite sizes of , and , for 1-step annealed, 2oC/Min and 1oC/Min, respectively. The broadened XRD spectrum of the as-deposited film is attributed to the presence of dangling bonds that act as trapping sites. Comparison of the measured values of the optical band gap with simulation from SCOUT at low annealing rates (2oC/min and 1oC/min) was found to decrease with enhancement in crystallite size, indicating a reduction in porosity and improvement in both densification and crystallinity of the films.
Keywords: Crystal Size, TiO2, band gap, photon energy, refractive index