CaCO3/TiO2 Nanoparticles Based Dye Sensitized Solar Cell

In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells (DSSCs), have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 degrees of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo-electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on TiO2 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency (eta) from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm(2).