How to Make a Solar Cell From Scratch

Ever wish you could build your own solar power collectors? While these solar cells homemade from scratch may not do much to power lightbulbs or appliances, they will demonstrate the principle of semiconductivity that makes solar cells possible. This experiment will enthrall kids and adults alike and can be easily carried out in one afternoon with nothing more than household materials and a couple of sheets of copper flashing from the home improvement store.

Things You'll Need

• 2 4-by-4-inch sheets of clean copper flashing
• 2 sets of alligator clip leads
• Electric hot plate or stove
• 1 quart or larger wide-mouth glass Mason jar
• Table salt
• Micro-ammeter

Instructions

1. Place one piece of copper flashing on your electric burner and turn the burner on high. Wait until the burner gets red hot, then cook the copper for half an hour. It should turn completely black.

2. Turn the burner off and leave the copper in place to cool off. Most of the black coating, which is cupric oxide, will pop off on its own. Gently remove more of it by scrubbing the copper between your hands under running water. Don't worry about getting every little bit of black off; it's more important to preserve the red layer of cuprous oxide below it.

3. Bend the burned sheet of copper and the unburned sheet of copper so that they will fit inside your glass mason jar without touching.

4. Fill the glass jar with hot tap water so that about an inch of each copper sheet protrudes from the water. Add 3 tbsp. of salt.

5. Connect one alligator clip between the unburned copper flashing and the positive terminal of your micro-ammeter. Connect the other lead between your burned copper flashing and the negative terminal of the micro-ammeter. Make sure that the two sheets of copper flashing aren't touching but are both submerged in the salt water solution.

6. Move the solar cell you just made from scratch into the sun and observe the readings on the micro-ammeter. Your creation is also a weak battery, so it will display a little bit of current even in the shade but should show significant spikes when exposed to the sun.

Tips & Warnings

• Don't leave the copper unattended on the stove.