Parameters determining efficiency and degradation of TiO2|dye|CuI solar cells

The influence of the micro-morphological structure of the TiO₂ film, the distribution of CuI in TiO₂ pores and the concentration of added surfactant in the CuI coating solution on the photocurrent of solid-state TiO₂|dye|CuI solar cells was examined by space resolved photocurrent imaging technique. Iodine is found to be competing with the oxidized dye molecules in accepting electrons from CuI and decreases the efficiency of the cell. TiO₂|dye|CuI cell degrade two hundred times faster than wet sensitization cells. This instability is considered to be due to the decomposition of the electron transfer-bridge between the sensitizer and CuI.