Fabrication of a Dye Sensitized Solar Cell and Its Performance Dependence on Temperature and Irradiance

This paper reports the temperature and irradiance dependence of dye-sensitized solar cells (DSSCs) with acetonitrile-based electrolytes. The prototyped DSSCs had nanocrystalline titanium dioxide photoanodes and platinum thin film cathode. The photoanodes were sensitized with N-749 dye. The current-voltage characteristics of the DSSCs were measured at temperatures from 5 to 50 °C and under 500, 1000, and 1500 W m⁻² irradiance. The open circuit voltage, V_OC, decreased linearly with increasing temperature and had positive, logarithmic relation with irradiance. At temperatures lower than 15 °C, short circuit current density, J_SC, was limited by the diffusion of I₃⁻ in the electrolyte and increased with increasing temperature. At higher temperatures the recombination of electrons injected into the TiO₂ conduction band was dominant over diffusion and J_SC decreased with increasing temperature. Moreover, J_SC increaed linearly with increasing irradiance. The DSSC photoconversion efficiency did not vary appreciably at temperatures lower than 15 °C but decreased with increasing temperature. Finally, the efficiency increased with increasing irradiance.