Finally : cheap DIY selfmade solar cell with common materials !

[andi742]

hey!
ok just a short thing again: there is no pn layer in the dsc as it is in a silicon solar cell!
of course you need the ito as well as the tio2 because you can't get the electron from the tio2 directly. you need a certain layer (ITO)  that is capable of conduct to a let's say copper wire!
http://en.wikipedia.org/wiki/Dye-sensitized_solar_cells
regards andi

[hartiberlin]

hey!
ok just a short thing again: there is no pn layer in the disc as it is in a silicon solar cell!
of course you need the ito as well as the tio2 because you can't get the electron from the tio2 directly. you need a certain layer (ITO)  that is capable of conduct to a let's say copper wire!
http://en.wikipedia.org/wiki/Dye-sensitized_solar_cells
regards andi

Hi Andi,
you always need a bandgap for the conversion of light in my experience.

I had in one experiment the TiO2 plus red tea extract first on a normal glas disc without ITO and after this layer
a graphite layer,which was conductive and was also wet in saltwater for the electrolyte,
but there was only galvanic effects of 0.3 Volts, but no light sensivity.
Okay, I did not use any Iodide solution as the electrolyte,
but in copperoxid solarcells you can also use saltwater as the electolyte, no Iodide
needed...

So I really think, that the bandgap between the ITO, which is a P-Layer semiconductor
and TiO2, which is a N-Layer semiconductor IS NEEDED.

Regards, Stefan.

P.S: But I will test it soon also with Iodide solution again.

[andi742]

could you please explain how you got the electric circuit with the graphite saltwater thing....
like: dye->tio2->ito->load->ito->graphite->iodine->dye (for the dsc)
saltwater simply not works because there is no redox couple - iodine has I- and (I3)-
you don't have anything like that with Na+ and Cl-
and the bandgap that you always talk about is the energy that the dye needs (and gets from the photon) to lift an electron from the normal state to the excited state!

you can really believe me ;-)
i worked on that topic for many many hundreds of hours! maybe read the wikipedia article and you will know what I want to explain to you

[hartiberlin]

Hi Andi,
just try this:

Mix TiO2 with vinegar and put it onto a NORMAL glas plate.
Then heat the glas plate and apply the dye.
Let the dye soak into the TiO2 and then let it dry.
Then use a burning candle to make a black graphite (lamp black) layer ontop of this TiO2.
This will be the conducting electrical current pickup layer.

Then soak this glas plate into the Iodine electrolyte and use with a bit distance
just graphite paper ( a mix of graphite and acrylic binder) as the second electrode.

Then use a light to shine onto the glas plate to see, if this cell is light sensitive.

Instead of the lampblack layer on the TiO2 you could also use a silver metal wire
or silver mesh to collect the current from the TiO2, if your arguments are
valid, but I guess, as the ITO-TiO2 is missing, there will be no PN-layer and thus
no conversion of light.
You will only see galvanic voltage effects.

Please also try it and let me know.

Many thanks.
Regards, Stefan.

[onthecuttingedge2005]

try optical brighters as your dye source and or fluorescent dyes.

some homemade LASER Dyes people use that might help in some solar cell experiments for dye type solar cells.

I've been looking into reasonable things for DIY laser folks, and so far I have two cheap and easy candidates, which I describe on Inexpensive Laser Dyes for the Do-It-Yourselfer. In case you want a quick precis, they are:


"Highlight" fluorescent markers. I've lased 2 or 3 of the available colors. The Sharpie "Accent" yellow-barrel marker (makes a yellow-green highlight) is probably the best I've found so far.

Several of the brighteners used in laundry detergents are good blue or indigo laser dyes. It is possible to use some liquid laundry detergents directly. I lased All “Free Clear” in 2000, using a low-pressure nitrogen laser; and Jarrod Kinsey has recently been getting very nice results with Arm and Hammer 2x liquid concentrate, pumping it with a TEA nitrogen laser.
If you try this, remember to use detergents that are listed as “No Dyes, No Perfumes”, and are as close to water-clear as possible: murky blue gunk is obviously not going to work. A few of the better organic detergents actually are free of dyes, including optical brighteners, so it’s a good idea to test for fluorescence before you buy, or look for the word “brightener” in the ingredient list. OTOH, most or all of the major brands, at least the ones that are transparent, appear to be good candidates.

You can, alternatively, make an alcohol extract of a dry powder detergent (I have gotten my best results with Arm and Hammer). This works extremely well, provided you can filter or centrifuge the extract to remove the remaining dusty bits of detergent. I believe that this method works best with 91% pure (or higher) isopropyl alcohol or 95% ethanol, but it may be possible to do it with 70% isopropyl rubbing alcohol.

Far and away, however, the best thing I've found along these lines so far is “Optic Whitener”, from Dharma Trading Co. A very small amount of this, diluted with isopropyl alcohol or ethanol, will fill a dye cuvette that is pumped by a nitrogen laser; and the bottle contains 8 ounces, so it will last several lifetimes. (I have not yet tried it in a flashlamp-pumped dye laser, but I will when I have time, and I'm confident that it will work nicely.)