Photoactive activity of different natural dyes for possible applications in solar cells

In this work, natural dyes extracted from mortiño and Jamaica flower originally from the Andean sierra of Ecuador were used as dye sensitizers in dye-sensitized solar cells (DSSCs). In addition, two kinds of counter electrodes were used, SWCNTs and candle soot films on fluorine-doped tin oxide (FTO) coated glass. The optical properties of the dyes obtained from a simple extraction process using ethanol as solvent were investigated using UV-Vis spectroscopy. The structure of the titanium dioxide (TiO2) film at the photoanode and the SWCNTs film at the counter electrode were characterized using X-ray powder diffraction (XRD) and Raman spectroscopy. It was found that the film deposition process of SWCNTs, involving a gel coating using polyethylene glycol (PEG) as binder, does not introduce defects or strong doping in the crystalline structure of the SWCNTs. The photovoltaic performance of the fabricated cells was evaluated from their I-V curves and photovoltaic parameters as maximum power output (Pmax), fill factor (FF) and power conversion efficiency (η). The DSSCs using the SWCNTs film as counter electrode exhibited the highest Pmax, FF, and η values due to a low charge transfer resistance and better electrocatalytic activity from a higher surface area. Finally, the effect of the sensitization time of the TiO2 film on natural dyes is studied. By increasing the sensitization time to 20 hours, the spectral response of TiO2 to visible light with an increase of η by a factor of 2.65

• Prif Awdur: Romero Proaño, Pablo Andrés (author)
• Fformat: bachelorThesis
• Iaith: eng
• Cyhoeddwyd: 2021
• Pynciau: Sensibilizador; Celdas solares sensibilizadas por colorantes; Nanotubos de carbono; Fotoánodos; Rendimiento fotovoltaico; Sensitizer; Dye-sensitized solar cells; SWCNTs; Photoanode; Photovoltaic performance
• Mynediad Ar-lein: http://repositorio.yachaytech.edu.ec/handle/123456789/418