The effect of temperature on the performance of dye-sensitized solar cells based on a propyl-methyl-imidazolium iodide electrolyte

The performance of dye-sensitized solar cells (DSSC), based on an ionic liquid (propyl-methyl-imidazolium iodide) electrolyte, has been evaluated at varying iodine concentrations and cell temperatures (5-50 degrees C) for two irradiancies (0.1 and 1 sun). At 1 sun and at lower temperatures, the short-circuit current (J(SC)) is limited by the diffusion of tri-iodide, while at higher temperatures, the J(SC) decreases due to more pronounced recombinations. Also, the conversion efficiency of a DSSC resembles the J(SC) behaviour. At 0.1 sun irradiance, the efficiency monotonically decreases with increasing temperature, while at I sun, a five-fold increase in efficiency is observed. (C) 2007 Elsevier B.V. All rights reserved.