take two
I attempted to make a solar cell with aluminium rear electrode coated with TiO2 and a conductive plastic ITO sheet at the front.
7% vinegar and Titanium Dioxide
The slurry applied to the aluminium sheet
I used a vinegar 7% and Ti02 to make a slurry then doctor bladed a layer onto the freshly sanded thin aluminium sheet. Some of the issue of working with thing flexible sheets became apparent. The aluminium had small divots and dimples which resulted in an uneven spread of TiO2. Then the slight bow in the sheet meant that when it was placed on the hotplate, it was not heated evenly. After 20mins on the hotplate on max ( actual temp unknown) the TiO2 blackened and then became lighter. However it never turned bright white and always remained slightly yellowed.
Fixing the TiO2 on the hotplate
In order to dye the TiO2 I came across a tub of mashed raspberry in the freezer . After adding some to a bowl of ice cream I also placed some bowl for 10mins along with the coated aluminium sheet. After washing the pulp off the sheet it seems as though the dye did not stain the titanium. SO it was placed back in with the berries for another 20mins. Then I realised that the mashed berries where left overs from making raspberry cordial by placing them in a steamer. It seemed likely that the juicing process removed most of the dye we were after.
Raspberry pulp has not stained the TiO2
After further hunting in the freezer whole raspberrries that had not been juiced where found. However, after 20mins the titanium was still relatively unstained. One thought was that the amount of dye that was taken up by the titanium was more difficult to see as the aluminium was opaque as opposed to the conductive glass.
Using whole berries, but still not staining
Covering the front anode with carbon by drawing on it with a pencil did not seem to work on the softer conductive plastic. So graphite was scraped off a pencil and then adhered to the damped plastic.
The resultant cell did not change at all under torch light
Drops of 2% Iodine tincture were placed on the titanium and then covered with the transparent plastic. After wiring the cell up to a multimeter a torch was switched on and “hey presto!" ⚡️ Absolutely nothing happened. Not surprising really given the number of issues along the way.
