Enhancing Power Conversion Efficiency of Dye-Sensitized Solar Cell Using TiO2-MWCNT Composite Photoanodes

The aim of this work is to improve the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs) using composite films consisting of titanium oxide (TiO₂) nanoparticles and multiwalled carbon nanotubes (MWCNTs). A transmission electron microscope (TEM) was used to confirm the dispersion of carbon nanotubes (CNTs) in TiO₂. Composite photoanode-based solar cells were characterized by UV–Visible absorption spectroscopy, photocurrent–voltage (I–V) characteristics, and electrochemical impedance spectroscopy. It was found that the PCE ($\eta _{c}$) of DSSCs strongly depends on the concentration of CNTs in the nanocomposite films. The solar cell assembled with photoanode containing 0.06% MWCNTs shows the highest efficiency of 5.25%, which is 46% greater than unmodified photoanode. The density functional theory (DFT) quantum modeling technique was used to compute the band gap of TiO₂ and CNT-TiO₂ clusters.