The photovoltaic performance of dye-sensitized solar cells was investigated by incorporation of Al2O3 impregnated multi-walled carbon nanotubes (MWCNTs) and without impregnated MWCNTs in TiO2. The composites of Al2O3-MWCNTs and MWCNTs with TiO2 were prepared by a direct mixing technique. The dispersions of Al2O3-MWCNTs and MWCNTs in TiO2 were confirmed by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) analysis confirms the interstitial incorporation of carbon atoms in the TiO2 lattice via O-Ti-C and Ti-O-C surface states. The solar cells assembled by using composite photoanodes were characterized by UV-Visible absorption spectroscopy measurement, photocurrent-voltage characteristics, and electrochemical impedance spectroscopy. The results showed that upon optimization the device made of Al2O3-0.10%CNTs/TiO2, 0.10%CNTs/TiO2 and pristine TiO2 showed an overall conversion efficiency of 7.02, 5.94 and 5.02 respectively. The improvement in the efficiency of Al2O3-MWCNTs/TiO2 based DSSC can be attributed to an enhanced short-circuit current and reduction in charge recombination. We also employed density functional theory (DFT) to find the band gaps of Al2O3-CNTs/TiO2, CNTs/TiO2 and pristine TiO2.
- Density functional theory
- electrochemical impedance spectroscopy
ASJC Scopus subject areas
- Chemical Engineering(all)