Pyrocatechol violet sensitized cadmium and barium doped TiO₂/ZnO nanostructures: As photoanode in DSSC

Cadmium and barium doped TiO₂ nanoparticles and their respective heterostructured nanomaterials (TiO₂/ZnO) were successfully synthesized through simple sol-gel and reflux methods respectively. Optical, structural and morphological analysis of as synthesized material were done by using UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-Ray analysis (EDX). The band gap values were calculated from the optical absorption spectra of nanomaterials. The band gap of TiO₂ NPs (3.10 eV) was effectively tuned up to 2.82 eV by doping it with different concentrations of cadmium and barium followed by coupling with ZnO nanoparticles. The crystalline nature and phase purity of the materials were confirmed through XRD. Morphological analysis and elemental composition studies were performed with the help of SEM and EDX. Functional groups were detected through FTIR analysis. The nanostructured materials were used in combination with P3HT (as a hole conducting polymer) to fabricate photoactive blend for dye sensitized solar cell. The photovoltaic performances of fabricated device were investigated by using current voltage (I–V) measurements. The results showed that metal doped TiO₂ and their respective nano structures (TiO₂/ZnO) showed better conversion efficiencies than undoped TiO_2. The maximum conversion efficiency (ɳ) was observed for Pyrocatechol violet sensitized Cd–TiO₂/ZnO heterostructured nanomaterial which is 1.84%. The corresponding current density was found to be 13.11 mA/cm².