Photoanode annealing effect on charge transport in dye-sensitized solar cell

Solar energy is an abundantly available form of clean and renewable energy resource that can be used to generate electricity using many different photovoltaic technologies. Dye-sensitized solar cells (DSSCs) have attracted attention of researchers due to their low cost and easy fabrication processes, when compared to conventional silicon-based photovoltaic devices. Performance enhancement of DSSCs continues to be the subject of recent research. In this work, FTO/TiO2/N719/electrolyte/Pt-type conventional DSSCs were fabricated with and without heat treatment of the FTO/TiO2 photoanode before sensitization and Pt counter electrode. Results of the photovoltaic and impedance spectroscopic measurements are reported and discussed. The photovoltaic data reveals relatively higher performance of the cell made after heat treatments of the photoanode and the counter electrodes. The objective of this research is to study the reason for high performance obtained employing the annealed photoanode. The overall power conversion efficiency and short-circuit current density of the device made after heat treatment are observed higher than the one without heat treatment by 165% and 206%, respectively. The impedance spectroscopic studies also confirmed high performance of the cell made after the heat treatments.