6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Investigation of Co-synthesized Natural Dye Sensitizers using Symphytum officinale and Bidens pilosa in Dye-Sensitized Solar Cells

7 Jul 2026, 11:00
20m
Lecture Hall DL3 (University of the Western Cape)

Lecture Hall DL3

University of the Western Cape

Oral Presentation Track F - Applied Physics Applied Physics

Speaker

Ronel Ronella Randela (University Of Venda)

Description

Dye-sensitized solar cells (DSSCs) are a type of photovoltaic device that uses light-absorbing dyes to convert sunlight into electricity, offering a low-cost, environmentally friendly alternative to conventional silicon- and ruthenium-based solar cells. This study investigates the co-sensitization potential of natural dyes extracted from Symphytum officinale and Bidens pilosa for application in a DSSCs. The dyes were extracted using ethanol and applied individually and in combination. Optical properties were analyzed using UV–Visible spectroscopy, which revealed that Symphytum officinale exhibited absorption peaks associated with chlorophyll in the red and blue regions. In contrast, Bidens pilosa showed absorption in the lower-wavelength region due to flavonoid and carotenoid compounds. The co-sensitized extracts exhibited a broader absorption spectrum, suggesting improved light-harvesting efficiency. Functional group analysis was performed using Fourier Transform Infrared (FTIR) spectroscopy, confirming the presence of hydroxyl (–OH), carbonyl (C=O), and aromatic (C=C) groups, which are crucial for effective interaction with Semiconductors. X-ray Diffraction (XRD) indicated that the extracts were predominantly amorphous, with no significant crystalline peaks. Overall, the results suggest that co-sensitization of Symphytum officinale and Bidens pilosa enhances the optical absorption range but does not significantly improve structural properties. The findings highlight the potential and limitations of using synthesized natural dyes in DSSCs applications, emphasizing the importance of molecular composition and binding characteristics in determining performance.

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Authors

Ronel Ronella Randela (University Of Venda) Dr Tshifhiwa Ranwaha (University Of Venda) Dr Lutendo Mathomu (university of venda) Eric Nnditshedzeni Maluta

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