Solar cells convert solar energy into electricity, in the same way that plants convert sunlight into food through photosynthesis. Photovoltaic panels use the sun to excite electrons in a semiconductor, causing it to move from an orbit closer to the nucleus to a higher one. Commercial panels use silicon as a semiconductor, but in this article we will look at a way to build one with more accessible materials.
Steps
Method 1 of 3: Treat the glass
Step 1. Get two pieces of glass of the same size
The microscope slides are perfect.
Step 2. Clean them with alcohol
Once cleaned, handle them by the edges.
Step 3. Measure its conductivity
Touch the surface of the slides with the tips of a tester. Once you have established which side is the most conductive, couple the slides with the conductive side on the outside.
Step 4. Join the slides using tape on the inside
Step 5. Apply titanium dioxide solution to the slides
Put two drops on each side and distribute them evenly.
You can improve the grip of the titanium dioxide by first applying a coat of tin oxide
Step 6. Remove the tape and separate the two slides
Now you will need to treat them separately.
- Place one on an electric grill overnight to cook the titanium patina.
- Wash the other one and put it away from dust.
Step 7. Prepare some dye in a flat plate
You can use raspberry, blackberry, or pomegranate juice, or an infusion of hibiscus petals.
Step 8. Place the titanium-coated slide in the dye, painted side down
Soak for ten minutes.
Step 9. Clean the other slide with alcohol
Do this while the other slide is soaked in the dye.
Step 10. Double check the conductivity with the tester
Draw a + with a marker on the less conductive side.
Step 11. Apply a carbon coating on the conductive side
You can do this by passing a pencil over the surface, or by applying a graphite-based lubricant. Cover the entire surface.
Step 12. Take the titanium dioxide treated slide out of the dye dish
Rinse it twice, first with deionized water and then with alcohol. Wipe dry with a clean cloth.
Method 2 of 3: Assemble the panel
Step 1. Place the carbon-treated slide on top of the titanium-treated slide, so that the two coatings are in contact
Offset the two slides by about 5mm. Use clothespins on the long side to hold them together.
Step 2. Apply two drops of iodinated solution to both slides
Let them soak completely. Open them slightly to allow the liquid to penetrate better.
The iodinated solution will allow electrons to pass from the titanium-treated slide to the carbon-treated slide when exposed to a light source. This solution is also called "electrolytic"
Step 3. Eliminate the excess solution
Method 3 of 3: Activate and test the panel
Step 1. Attach a crocodile clip to each of the two slides
Step 2. Connect the black tester lead to the titanium-treated glass slide
This is the negative electrode of the panel, i.e. the cathode.
Step 3. Connect the red tester lead to the carbon-treated glass slide
This is the positive electrode, or anode (you previously marked the slide with a +).
Step 4. Expose the solar cell to a light source, with the cathode facing the source
If you are in school, you can place the slides on the lens of a projector. At home you can use another lamp or the sun itself.
Step 5. Measure the current and voltage generated by the panel with the tester
Measure before and after exposure to light.
