Solar cells convert solar energy into electricity. Like plants, they convert solar energy into food through photosynthesis. Solar cells work by using the sun's energy to make electrons in semi-conducting materials move from orbits close to the atomic nucleus to higher orbits to generate electricity. Commercial solar cells use silicon as a semi-conductor, but there is one way to make solar cells with more readily available materials for you to see for yourself how it works.
Step
Method 1 of 3: Coating the Glass Slab
Step 1. Prepare 2 glass slabs of the same size
Glass slabs the size of the glass commonly used for under the microscope are ideal for use.
Step 2. Clean the surface of both plates with alcohol
After cleaning, just hold the edges.
Step 3. Test the surface of the slab for conductivity
The trick is to touch the surface with a multimeter. After determining which side is conductive, place it side by side, one conductive side facing up and the other conductive side down.
Step 4. Glue transparent tape on both slabs
The tape will keep the slab in the same position for the next step.
- Glue the tape along the long sides of the two slabs with an excess of 1 millimeter from the edges.
- Stick the tape 4 to 5 millimeters away from the conductive side of the slab.
Step 5. Drop the titanium dioxide solution onto the plate
Drop 2 drops on the conductive side of the slab, then spread it over the entire surface of the slab. Place titanium dioxide to seal the lower conductive side of the slab.
Before dripping titanium dioxide liquid, you can coat it with tin oxide
Step 6. Remove the tape and separate the plates
Now you handle the 2 slabs differently.
- Place the slab with the conductive side up on an electric hot plate overnight to roast the titanium dioxide over the slab.
- Clean the titanium dioxide from the plate with the conductive side down and place it where it will not get dirty.
Step 7. Prepare a saucer or flat plate filled with dye
The dye can be made from raspberry, blackberry or pomegranate juice or by brewing tea from red hibiscus petals.
Step 8. Soak the titanium dioxide-coated plate, titanium dioxide-coated side down, in the dye for 10 minutes
Step 9. Clean the other plate with alcohol
Perform this step while the titanium dioxide-coated plate is soaking.
Step 10. Retest the conductivity of the cleaned slab
Mark the non-conductive side with a plus sign (+).
Step 11. Coat the conductive side of the cleaned slab with a thin layer of carbon
You can do this by covering the conductive side with a pencil or using graphite lubricant. Cover the entire surface.
Step 12. Remove the titanium dioxide-coated plate from the dye
Rinse twice, first with de-ionized water then with alcohol. After rinsing dry with a clean tissue.
Method 2 of 3: Assemble the Solar Cell
Step 1. Place the carbon-coated plate on top of the titanium dioxide-coated plate so that the two coatings meet face to face
The plates should be about 5 millimeters apart from each other. Use a binder clip on the long side so it doesn't change its position.
Step 2. Drop 2 drops of liquid iodide on the exposed layer
Allow the liquid iodide to cover the surface. You can open the binder clip and gently lift 1 slab up so that the diode liquid covers the entire surface.
The liquid iodide will cause electrons to flow from the titanium dioxide-coated plate to the carbon-coated plate when exposed to light. These fluids are called electrolytes
Step 3. Wipe off excess liquid from the slab
Method 3 of 3: Activate and Test Solar Cell
Step 1. Glue the alligator clip on the layered part on one side of the solar cell
Step 2. Connect the black wire from the multimeter to the clip connected to the titanium dioxide coating
This plate is the negative electrode or cathode of the solar cell.
Step 3. Connect the red wire of the multimeter to the clip that connects to the carbon layer
This plate is the positive electrode or anode of the solar cell. (In the previous step, you marked it with a plus sign on the non-conductive side.)
Step 4. Place the solar cell near the light source, with the negative electrode facing the light source
In a school classroom, this method can be done by placing a solar cell above the projector lens. At home, use other light sources such as spotlights or the sun.
Step 5. Measure the current and voltage generated by the solar cell with a multimeter
Do this before and after the cells are exposed to light.
