Acetic acid and corrosion

[Schneizel]

Hello,

I have completed a 36 cell panel with acetone cure silicone sealant on the back and edges of the solar cells. Having gone through the process of making the panel, I'm thinking of alternatives that can be used for weatherproofing the solar cells. Now I have a burning question: what part of the solar cell is actually corroded by acetic acid that is released by household silicone sealants? Is it only the silver parts that are corroded or is there more to it?

[peakbagger]

There is another variety of silicone called "neutral cure" with no acetic acid, I think it uses alcohol to cure.

[Mike90250]

Both the total front side and backside, are plated with metal (often aluminum, with something solderable printed/silkscreen in "finger" grid to collect the power). The frontside layer is only a couple atoms thick, to allow light through. If the acid eats away any of that, your cell looses capacity.

The acetone (neutral cure)sealer is fine, but does not seal out water vapor, which in a couple years, eats away the metal plating on the front side. = dead cell.

[Schneizel]

Can I just clarify that only the white color grid is affected by the corrosion on the front side and the blue color surface is spared?

I'm thinking of sealing the front with a waterproof, non vapor permeable, transparent material and then sealing the back with normal acetic cure silicone sealant.

Would the acetic acid attack the gray colored back or only the solder points in white?

Thanks for shedding some light on this

[Mike90250]

acetic acid is a fancy name for vinegar. Soak your samples in vinegar for a couple days and see what you think. Acid & electricity do not mix, except inside a LEAD-ACID battery.

Acid sealed to a cell by sealer, is just going to sit there, eating it away.

[Schneizel]

I'm sorry if i did not make my question clear. The primary question is which layer (ie conducting layer, semiconductor layer, etc) of the solar cell is corroded by the acid.

[Mike90250]

The conducting layer goes first, since it's only atoms thin (transparent)