Sciencemadness Discussion Board

why Iodine is used as electrolyte in dye sensitized solar cell

green - 29-9-2010 at 21:30


why Iodine is used as electrolyte in dye sensitized solar cell? why not use some other. any sugestion please

psychokinetic - 29-9-2010 at 23:47

When I2 meets UV, it breaks up into I- ions, which are brilliant for doping conductive polymers.

Might not be the answer, and it depends on whether the solar cell uses any conducting polymers....

Cloner - 29-9-2010 at 23:51

Iodine is not merely a conducting electrolyte, it is reversibly reduced and oxidized in this type of solar cell. I2 / 2 I- has just about the right redox level. Matching energy levels properly is crucial for these cells. Too little potential loss and the current is too small, too much potential loss and the energy yield suffers.

The problem with iodine solution is that it is liquid state, and solid state is preferred for engineering reasons.

[Edited on 30-9-2010 by Cloner]

green - 30-9-2010 at 04:12

thank you for the response. Cloner you have mentioned that having iodine in liquid state is not desirable for long term stability. can you think of anything else to replace it with solid state electrolyte.
psychokinetic also pointed out about use of conducting polymer in solar cell, do you think doping conductive polymer with iodine will solve the problem of using liquid electrolyte in solar cell. could you please elaborate on that. thank you

not_important - 30-9-2010 at 09:43

Doped polymers have been tried, and have difficulties of their own, I believe in part to low mobility of the ions involved and failure to contact as much surface of the TiO2. Ionic liquids have been investigated as another way of improving the usefulness of iodine/iodide based cells, and iodine-free approaches.

There's a bit on the subject here

http://pubs.acs.org/doi/abs/10.1021/ar900069p

psychokinetic - 30-9-2010 at 11:40

Quote: Originally posted by Cloner  
Iodine is not merely a conducting electrolyte, it is reversibly reduced and oxidized in this type of solar cell. I2 / 2 I- has just about the right redox level. Matching energy levels properly is crucial for these cells. Too little potential loss and the current is too small, too much potential loss and the energy yield suffers.
[Edited on 30-9-2010 by Cloner]


That makes a lot more sense. As Not Important said, the idea of using the I- is difficult.

[Edited on 30-9-2010 by psychokinetic]