Effect of imidazolium salts on the performance of solid-state dye-sensitized photovoltaic cell using copper iodide as a hole collector

A promising and cheaper alternative to the silicon solar cell, is the dye-sensitized photo electrochemical cell and a solid-state dye-sensitized cells using p-CuI as the hole-conductor has advantages to conventional wet-type cells for practical use. However, this n-type semiconductor/Dye/p-type semiconductor device has problem of the long-term photostability. In this paper, the results of addition of several 1-ethyl-3-methylimidazolium (Im) salts and the effect of their counter anions on the performance of the cell are described. We improved the performance and stability of the solid-state dye-sensitized solar cell using CuI with ImSCN whereas other Im salts showed only slight effect except for ImI.