Browsing by Author "Makangara, John"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Optical and photovoltaic properties of substituted alizarin dyes for dye-sensitized solar cells application
    (Taylor & Francis, 2020) Abubakari, Ismail; Babu, Numbury Surendra; Vuai, Said; Makangara, John
    This paper presents the theoretical study on photovoltaic and absorption properties of alizarin derivatives. Optimization of structures and calculations were performed by density functional theory and time-dependent density functional theory using B3LYP hybrid functional and 6–31 G (d,p) basis set. The dyes were formed by substituting 2-hexylthiophene mixed with carboxylic acid and 4-(benzo[c][1,2,5]thiadiazol-4-yl)benzoic acid. The performed substitution shows improvement in most of the properties. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of molecular dyes showed positive effect upon electron injection to semiconductor and subsequent regeneration by the electrolyte. Almost all necessary and important parameters to demonstrate the usefulness of molecular dyes as photo-sensitizers are detailed discussed. Based on the discussion and analysis, all considered molecules are proved to be useful in dye-sensitized solar cells using TiO2 semiconductor and I−/I−3 couple electrolyte. Collectively, dyes DY3 and DY2 showed better results than others with LHE and V oc of 0.2142 and 0.6722 eV, respectively, for DY3 and 0.7033 and 0.6224 eV, respectively, for DY2.
  • Thumbnail Image
    Item
    Synthesis and photocurrent density–photovoltage (J–V) characterization of a novel alizarin derivative dye for dye-sensitized solar cell technology
    (Springer, 2022) Abubakari, Ismail; Babu, Numbury Surendra; Vuai, Said; Makangara, John
    Dye-sensitized solar cells technology has attracted extensive academic scholars’ interests due to their potential low-cost solar energy harvesting. Increasing performance of dye-sensitized solar cell needs more efficient dye to maximize solar energy absorption. This work presents the synthesis and J–V characterization studies for a novel alizarin derivative dye HDD. The dye was formed by the reaction between brominated alizarin and 5-hexyl-2-thiopheneboronic acid pinacol ester. The final dye product was successfully synthesized as brownish-orange solid. Characterization of the synthesized dye was done using spectroscopic techniques; mass spectrometry, infrared spectroscopy and nuclear magnetic resonance before photovoltaic performance investigation. The dye was found to be useful as photo-sensitizer in dye-sensitized solar cell through calculation of conversion efficiency. Generally, the dye HDD showed better results in terms of photovoltaic properties with open-circuit voltage, short-circuit current density and fill factor of 0.65 V, 0.0146 A/cm2 and 0.612, respectively. The conversion efficiency of the cell using the synthesized dye HDD was found to be 5.81% under 100 mW/cm2 solar illuminations.