Introduction: DIY Solar Cell From Scratch

Hello! In this instructable I will be showing you how to create a solar cell! I must warn you, the end product does not have any esthetic appeal whatsoever and is far from an professionally produced solar cell, but it works! This instructable will cover everything from gathering materials to measuring the output of your newly created solar cell.

According to Wikipedia a solar cell or photovoltaic cell is “an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Solar cells are the building blocks of photovoltaic modules, otherwise known as solar panels.”

The photovoltaic effect the creation of voltage or electric current in a material upon exposure to light.

Step 1: Gathering Materials

Like any project there is a shopping list, most of these items are household items or tools, and you will most likely already have them. I recommend vendors on eBay for items like the glass plates and titanium dioxide.

- Titanium Dioxide (white powder, often used in make-up)

- 2 Binder clips (to hold the plates together)

- Acetone or rubbing alcohol

- Glass plates*

- Graphite powder/pencil/lubricant stick

- Syringe (not a must, just handy)

- Multi meter

- Cotton pads/swabs

- Alligator clips

- Aluminum profile (or something straight, non-porous like a piece of hard plastic)

- 2 dishes, both shallow

- Spoon

- Demi water (de-mineralized water)

- Raspberry, blueberry or blackberry juice (has to be made directly from the fruit! no processed juices!)

- Iodide solution

- Cooktop/hotplate

The total cost of this project was about 30 dollars for me, as I had quite a lot of the items on the list already.

*These glass plates need to be covered (on one side) in tin oxide (SnO2) this makes the plates conductive which is important. Searching “conductive glass“ on eBay gives some good results.

Step 2: Cleaning the Plates

After you have collected all the items for the solar cell you can start building!

Find a clean surface to work on.

Put some acetone on one of the cotton pads and clean both sides of the first plate. After both sides are cleaned only pick up the plates by the sides! Place the plate on the cotton pad and pull out the multi meter; you want the dial on a setting that detects short circuit. Test the plate for conductivity on the top slide, if the top is conductive place it somewhere clean. If it’s not conductive flip it over and try again, this time you should have the conductive side.

For the other glass plate just repeat the process, clean it on both sides and test it for conductivity. This time you want the conductive side down so it stays as clean as possible. Place this plate to the side as well and put the first plate (conductive side up) back in front of you.

Step 3: Titanium Dioxide

For now you can leave the conductive side down plate to the side, we won’t be needing it until the end.

The conductive side up plate however Is going to be coated in titanium dioxide. First take one of the dishes and pour in a little water. Next, start adding a little titanium dioxide to the water, frequently stirring. You want to remove all the lumps from the titanium dioxide. You will know you have the right consistency when the liquid turn into almost a goo.

Once you have made this titanium dioxide “goo” take a little out of the bowl with the spoon and place it on the plate, try to spread it out a bit but don’t get to close to the edges.

Now we want to equally cover the entire surface. We are going to achieve this by place 2 items slightly taller than the plate on either side of the plate (I used 2 stacked plates) and going over it with the aluminum profile or whatever you chose as your “straight, non-porous material. Doing this we cover the entire surface in an equal layer. If it spills a bit over don’t worry about it.

Once the plate is covered, we need to “bake” the titanium dioxide to the plate. Carefully move you plate to your cooktop or hotplate. Slowly warm it up so the glass has no chance of breaking. When it’s up to temperature leave it for a few hours so it has the chance to bake onto the plate.

Step 4: Finishing Up the Plates

Once the titanium dioxide is baked on we are only about 15 minutes away from a solar cell.

Take the berry juice and put it in the other shallow dish. Put the plate in with it so the juice covers the titanium dioxide. Leave this to soak for about 10 minutes. The berry juice/titanium dioxide is what produces the electrical current, When light hits the juice it creates a negative electron and a positive "hole" and normally speaking these would just bind to become neutral again. Instead of binding the titanium dioxide transports the electron to the terminal (alligator clip) which transports it further to the rest of the circuit.

In the meantime go back to the plate that was put aside (conductive side down). Flip it over and clean the surface one last time with a cotton swab and acetone. Now take the graphite pencil/lubricant and cover the enite surface of the CONDUCTIVE side with graphite.

Go back to the titanium dioxide plate, take it out of the juice and rinse it with demi water. To get all the liquids off DAB it with a cotton pad. I was so stupid as to wipe the plate; most of the titanium dioxide came off my plate. Don’t make the same mistake!

Note: This step is not really well documented with pictures. The picture shows the “graphite plate” covered in graphite powder. This is not how you want you slide, you need to spread it out and rub it into the plate.

Step 5: Putting It All Together

After the last step the plates are ready to be put together. Place the plates on each other but leave about half a centimeter on both plates exposed so you can attach it to the alligator clips (see first and second picture).

Hold the plates together with the binder clips; place them on the sides. There is one last thing we need to do to get good conductivity between the plates. Take off one of the binder clips again and put a few drops of the iodide solution on the sides of your creation so it gets between the plates, this will successfully electrically bond the plates. Absorb any iodide solution that did not go in between the plates with a cotton swab.

Congratulations! You have now created a solar cell!

You can measure the output of the cell by attaching alligator clips to both of the exposed parts of the plate and to the leads of the voltmeter (dial now set to millivolts). mine generates about 25 millivolts when exposed directly to sunlight (simulated with a lamp)

You have now created a working solar cell!

This could
be the start of something bigger, one individual cell does not produce a lot of electricity but if you were to make multiple larger versions of these it could really produce quite some electricity. Use your imagination!

Feel free to leave any suggestions in the comment section!

~Alex

Comments

author
RachelZ1 (author)2017-04-27

Is there any product other than iodide solution I can use

author
springyee (author)2017-01-22

This is super cool~ our group in physics want to use this as our passion project, is that ok with you? we'll give you full credits:) and add on our own research

author
honey181 (author)2015-05-28

Nice illustration dude! May i have ur email ID.??

author
akolk1 (author)honey1812016-03-18

I like to keep instructables on instructables, so if you have a question you can send me a message on here!

author
SamyE2 (author)akolk12016-08-11

Is there a way to make this conductive glass?

or I have to buy it??

author
Jacoby Anderson (author)SamyE22017-01-06

You have to order in online and wait a couple days for it to come.

author
Jacoby Anderson (author)2017-01-06

Hello. I love this project.

author
acondra2 (author)2016-08-15

When you get a chance use Poke Weed Berries for the dye. You will get twice the efficiency!

author
SamyE2 (author)2016-08-11

Is there a way to make this conductive glass?

or I have to buy it??

author
InvisibleIsle (author)2016-07-25

Hi! I have a few questions on your experiment because my group and I are hoping to make a solar cell out of soda lime glass. I hope you can answer my questions. I also hope you won't be bothered by my questions. Thank you!

What type of solar cell did you make?

What glass did you also use?

What is the chemical reaction needed to produce electricity?

Is it really necessary to use iodine in the solar cell?

What layering of chemicals is needed to make an alternative solar cell?

author
marialilokyee (author)2016-05-28

Hi, I'm making a solar cell following this instructable. I used crushed blueberries to be the dye, but it only gave little dye...Which berry juice did you use? Which fruit/berry juice give the greatest result?

author
holymohsen (author)2015-09-29

Is mixing gallium arsenid with juise increase performance if not what element is good?

author
akolk1 (author)holymohsen2016-03-18

I have not tried that, so i am not sure.

author
Just_the_science_Geek (author)2015-11-08

Sweet Dude!

Totally going to use this for my science project! Maybe even the future too! :P

author

You are very welcome to use it as your science project! if you have any questions just send me a message

author
timieno (author)2016-02-04

How much voltage did you work with please

author
akolk1 (author)timieno2016-03-18

25 millivolts

author
Kingdedon (author)2016-01-14

Pls sir is there any other good material to replace the glass?

author
BlueM2 (author)Kingdedon2016-02-14

I think just something can resist heat of light and transparent to let light go through....So i Think transparent plastic work as well?

author
akolk1 (author)BlueM22016-03-18

I would imagine that a clear plastic would work aswell, but because you have to "bake" the titanium dioxide on the plate plastic would not work well. But if you find a way to achieve the same result with plastic please share!

author
Tampaguy (author)2015-03-01

Really cool! I'm guessing that using "fruit juice" for this, it would not be a very permanent solar cell. Could you use 'something' to make it last a long time?

author
akolk1 (author)Tampaguy2015-03-01

I don't know, have you ever heard of OLED's? they are quite new to the market and are not widely produced yet. It's the same type of idea as the solar cell but turns electricity into light in stead of the opposite. These oled's do last a very long time so there are organic materials out there that last (a long time). I guess it's just a choice of material and means of preservation.

author
Tampaguy (author)akolk12015-03-04

Not familiar with OLEDs, but they sound really promising - I'll be looking into them. Thanks.

author
Kingdedon (author)Tampaguy2016-01-14

Sir pls what is the name of that conductive glass and what measurement of the glass will be used?

author
ProCactus (author)akolk12015-03-02

My 6year old phone has an OLED display.

I believe Philips made or used the first comercial OLED display in a shaver. You can see 'James Bond' use it in one of those very early movies.

author
ValeriaB1 (author)2015-09-05

Could you give more details about the specifications for the iodide solution please? Perhaps concentration, as well.

author
Cambenora (author)2015-03-01

Cool instructable.

What's the active ingredient in the fruit juice? I'm guessing it's either sugar or fruit acid (maybe citric acid). Could you refine that step to produce better results?

author
Billy.Cori (author)Cambenora2015-03-13

In fact the Berry juice have a kind of organic compounds that realize the solar light conversión, this compounds are called Anthocyanins. A type of phenolic compounds that brings color to fruits and flowers.

author
bdobrica (author)Cambenora2015-03-04

the active ingredient that binds to the titanium dioxide is porphyrin, a naturally occurring pigment: http://en.wikipedia.org/wiki/Porphyrin, mostly a complex organic molecule binding a metal atom inside that actually does all the work (and gives the color). try researching ”dye sensitized solar cells”.

author
akolk1 (author)Cambenora2015-03-01

there is no active ingredient in the juice, the solar cell utilizes the organic, light reactive properties of the berrys. I believe it has something to do with photosynthesis but i'm not entirely sure

author
charitou (author)2015-03-04

I wonder if someone could use a copper PCB instead of glass (titanium oxide-covered piece)...

author
chrwei (author)charitou2015-03-04

should work, but I'm not sure if it would be any better since one side still has to be transparent, and that's always going to be weak link...assuming the chemical part ins't the weak link, which it likely is.

author
chrwei (author)2015-03-04

this is known as a "Graetzel's cell". the fruit juice is used as the photosensitive dye, but commercial versions use a ruthenium-polypyridine based dye, which I can't find an easy source for.

author
BrownDogGadgets (author)2015-03-04

Very nice job!

author
gungajin (author)2015-03-02

just a thought: Instead of rinsing and dabbing the juice of, would it work to dry it with at hot air blower? That would eliminate the danger of damaging the titaniumoxide coating.

author
akolk1 (author)gungajin2015-03-02

absolutely! you don't want to dehydrate it though, liquid creates conductivity. but you dont want it soaked either because it will evaporate and break the seal. use the iodide to make a seal.

author
mvillalpando (author)2015-03-01

Great Instructable! I had always wondered how these cells were made. I'll be trying this out soon. Do you think that a 100% huney solution would work? After all, isn't honey one of the only foods that doesn't spoil. Or a mixture of huney and other juices?

author
akolk1 (author)mvillalpando2015-03-01

Thank you! I do not think honey will work. (I think) the reason you need to use fruit juices is because it contains cells that are part of photosynthesis. I don't think honey contains the same type of light sensitive cells.

A Mixture between the two is a idea though, the reason why honey doesn't go bad it that its mainly glucose and fructose (sugars) which, at such a high content, kill the bacteria. Adding it to the juice will kill the bacteria in the juice, preserving it. This process is calling "Candying". They use the same process to make jams and jelly's. Using jam or jelly is not advisable beacuse it probably does not retain the same properties after boiling.

If you can air proof the honey/fruit juice mixture it would probably last a very long time!

I would advise you to try both! they sound like interesting ideas and i'm curious if it would work.

hope this is of any help!

author
gungajin (author)akolk12015-03-02

I don't believe that berries are part of the photosynthetic proces. For that you need chlorophyl which is green. (there is a red variant though) But there is definitely a light-reactive agent in berries, that is what helps them ripe under sunlight and change color from green to whatever the final color may be.

Great instruction though! I love it, it has a lot of Mc Giver appeal ;-)

As for the longivity of organic materials, well, coal is organic, isn't it? Problem with organic materials is not that they wouldn't last but that they have a tendency of getting eaten by all sorts of animals, from bacteries to elephants.

author
Brajeshrai (author)2015-03-01

I think the juice will evaporate after exposing in the sun and it will stop working in a few days. what if we seal the edges with some glue or cement?

author
akolk1 (author)Brajeshrai2015-03-02

if you do it right the iodide schould create a seal but you can always glue it or whatever

author
DarkDecko (author)2015-03-01

Well this is one way to get off the grid :)

author
monkeyz (author)2015-03-01

at least now i know what to build with my raspberry ;-p

author
mnolan25 (author)2015-03-01

I think it also works with juice from ground up leaves such as lettuce

author
hpostlethwaite (author)2015-03-01

This is awesome, I'm looking forward to messing this up!

author
Michael_oz (author)2015-03-01

I imagine for spreading the graphite, putting another slide on top and rubbing together would work.

author
akolk1 (author)Michael_oz2015-03-01

absolutely! use something hard and flat, i used a butter knife. I would advise using a pencil though, loose graphite is a huge mess!

author
gmssb (author)2015-03-01

good job! you can do most ?

author
IanPerkins (author)2015-03-01

Very cool. Ive seen a few DIY instructions on making solar cells usually they are pretty complicated and utilize some exotic chemicals. The simplicity of this is awesome.

author
NewYorkRob (author)2015-03-01

I used strawberries and made juice. Worked just fine!

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Bio: Inventor, entrepreneur and student. I'm currently 19 years old and from the netherlands.
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