Effect on interfacial charge transfer resistance by hybrid co-sensitization in DSSC applications

TiO2 nanoparticles were synthesized by hydrothermal process to prepare metal oxide based photoanode for dye sensitized solar cell (DSSC) fabrication. X-ray diffraction analysis indicates the formation of tetragonal TiO2. High resolution transmission electron microscopy reveals the presence of agglomerated TiO2 particles and the average particle size is found to be 14 nm. The UV-Visible absorption spectrum ensures the absorption maximum at 268 nm. The band gap energy of TiO2 nanoparticles was found to be 3.3 eV which lies in the ultra-violet (UV) region. Impedance studies of TiO2 nanoparticles show an increase in conductivity with an increase in bias voltage. In the present work, the UV active TiO2 nanoparticles are employed for the fabrication of DSSC based on the hybrid co-sensitization of natural dye (Eugenia Jambolana) and organic dye (Eosin). The interfacial charge transfer resistance phenomena of the DSSC determined by electrochemical impedance spectroscopy is discussed in detail. Photovoltaic efficiency of 0.1377 % is achieved for the fabricated DSSC with co-sensitization of natural and organic dyes.